Explanation:
it's is d cause bromine can even react with water so
Bromine atoms have more electrons in their outer shell than calcium atoms. So the correct option is D.
What is valency?In chemistry, valence, usually spelled valency, is the characteristic of an element that establishes the maximum number of other atoms that one atom of the element may combine with. The phrase, which was first used in 1868, is used to indicate both the broad power of a combination of elements as well as its numerical value.
For 19th-century chemists, the explanation and systematization of valence posed significant difficulties. The majority of the work was focused on developing empirical guidelines for finding the valences of the elements because there was no good hypothesis for its origin.
The amount of hydrogen atoms that an element's atom may mix with or replace in a compound is used to quantify the characteristic valences of the various elements. But it soon became clear that various compounds had varied valences for numerous elements.
The identification of the chemical bond of organic compounds with a pair of electrons held jointly by two atoms and acting to hold them together in 1916 by the American chemist G.N. Lewis represented the first significant step in the development of a satisfactory explanation of valence and chemical combination. The German scientist W. Kossel studied the nature of the chemical connection between electrically charged atoms (ions) in the same year.
The theory of valence was reconstructed in terms of electronic structures and interatomic forces following the advent of the precise electronic theory of the periodic system of the elements. In response to the many ways that atoms interact, new notions such as ionic valence, covalence, oxidation number, coordination number, and metallic valence were developed.
Therefore the correct option is D.
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How much HCl is produced from the reaction of an excess of HSbCl4 with 3 moles H2S in the following reaction? HSbCl4 + H2S → Sb2S3 + HCl (Remember to balance the equation.)
Answer:
We will produce 8.0 moles of HCl , this is 291.7 grams HCl
Explanation:
Step 1: Data given
Number moles of H2S = 3.0 moles
Step 2: The balanced equation
2HSbCl4 + 3H2S → Sb2S3 + 8HCl
Step 3: Calculate moles HCl
For 2 moles HSbCl4 we need 3 moles H2S to produce 1mol Sb2S3 and 8 moles HCl
For 3.0 moles H2S we'll have 8.0 moles HCl
Step 4: Calculate mass HCl
Mass HCl = moles HCl * molar mass HCl
Mass HCl = 8.0 moles * 36.46 g/mol
Mass HCl = 291.7 grams
We will produce 8.0 moles of HCl , this is 291.7 grams HCl
From the balanced equation, it is determined that 2 moles of HCl are produced from 1 mole of HSbCl4. Therefore, 6 moles of HCl will be produced from the reaction of an excess of HSbCl4 with 3 moles of H2S.
Explanation:The balanced equation for the reaction is:
HSbCl4 + H2S → Sb2S3 + 2HCl
The mole ratio between HSbCl4 and HCl is 1:2, which means that for every 1 mole of HSbCl4, 2 moles of HCl are produced.
Since there is an excess of HSbCl4, we can assume that all 3 moles of H2S will react.
Therefore, the number of moles of HCl produced will be:
(3 moles H2S) x (2 moles HCl/1 mole HSbCl4) = 6 moles HCl
A 60g sample of tetraethyl lead, a gasoline additive, is found to contain 38.43g lead, 17.83g carbon and 3.74g hydrogen. Determine the compounds empirical formula.
Answer:
Empirical formula (which matches the molecular formula) is = PbC₈H₂₀
Explanation:
Our sample: 60 g of tetraethyl lead
In order to determine the compound empirical formula we need the centesimal composition:
(Mass of element / Total mass) . 100 =
(38.43 g lead / 60g ) . 100 = 64.05%
(17.83 g C / 60g) . 100 = 29.72%
(3.74 g H / 60g) . 100 = 6.23 %
These % are the mass of the elements in 100 g of compound. Let's find out the moles of them:
64.05 g / 207.2 g/mol = 0.309 moles
29.72 g / 12 g/mol = 2.48 moles
6.23 g/ 1 g/mol = 6.23 moles
Next, we divide the moles, by the lowest value of them (0.309)
0.309 / 0.309 = 1 mol Pb
2.48 / 0.309 = 8 mol C
6.23 / 0.309 = 20 mol H
There, we have our formula PbC₈H₂₀
For the reaction of A and B forming C, A(g)+ B(s)⇌ 2C(g) how will the reaction respond to each of the following changes at equilibrium? Drag the appropriate items to their respective bins.
a) double the concentration of B and halve the concentration of C.
b) double the concentrations of both products and then quadruple the container volume.
c) double the container volume.
d) double the concentrations of both products.
e) add more A.
f) double the concentrations of both products and then double the container volume.
The effects of changes in concentrations or volume on an equilibrium are predicted by Le Chatelier's principle. The reaction will typically shift to restore equilibrium in response to such changes. The exact direction of the shift depends on the specifics of the change in conditions.
Explanation:This question refers to Le Chatelier's principle, which allows predictions about how a change in conditions will affect a chemical equilibrium. (a) By doubling the concentration of B and halving the concentration of C, you are disrupting the equilibrium. The reaction will shift to the right (towards C) to reestablish equilibrium. (b) Doubling the concentrations of both products and quadrupling the container volume will decrease pressure, and the reaction will shift towards the side with more moles of gas, which is the right in this case. (c) Doubling the container's volume also reduces the pressure, again causing the reaction to shift to the right. Likewise, (d) the increase of products will shift the equilibrium to the left to minimize the effect. (e) Adding more A will cause the reaction to shift to the right, resulting in the formation of more C. (f) Doubling the concentrations of both the products and the container volume has two opposing effects. The added products would shift the reaction to the left, while the increased volume would shift it to the right. Thus, the final shift in equilibrium is dependent on which effect is greater.
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The equilibrium of the reaction A(g) + B(s) \<=> 2C(g) will shift to counteract changes such as concentration and volume adjustments, consistent with Le Chatelier's principle.
The response of the reaction A(g) + B(s) \<=> 2C(g) at equilibrium to various changes can be explained by Le Chatelier's principle, which states that a system at equilibrium will adjust to minimize any changes applied to it.
(a) If the concentration of B is doubled and the concentration of C is halved, the reaction would shift towards producing more C to counteract the decrease in C and to use up the extra B.(b) Doubling the concentrations of both products and then quadrupling the container volume will cause the reaction to shift left in order to increase pressure, thus favouring the side with more moles of gas, which is the reactants' side.(c) Doubling the container volume will decrease the pressure, so the reaction will shift towards producing more gas, thus shifting to the right towards more C.(d) Doubling the concentrations of both products will shift the equilibrium to the left, to reduce the concentration of the products and form more reactants.(e) Adding more A will shift the equilibrium to the right, to form more products and reduce the increased concentration of A.(f) Doubling the concentrations of both products and then doubling the container volume will have the net effect of no change in concentration due to volume change, but the initial doubling of products will still cause a left shift in the equilibrium.You need a 40% alcohol solution. On hand, you have a 100 mL of a 25% alcohol mixture. You also have 65% alcohol mixture. How much of the 65% mixture will you need to add to obtain the desired solution
Answer: 60 ml of the 65% mixture will you need to add to obtain the desired solution.
Explanation:
According to the dilution law,
[tex]C_1V_1+C_2V_2=C_3V_3[/tex]
where,
= concentration of given alcohol solution = 25 %
[tex]V_1[/tex] = volume of given alcohol solution = 100 ml
[tex]C_2[/tex] = concentration of another alcohol solution=65 %
[tex]V_2[/tex] = volume of another acid solution= x ml
[tex]C_3[/tex] = concentration of resulting alcohol solution = 40 %
[tex]V_3[/tex] = volume of resulting acid solution = (100+x)
[tex]25\times 100+65\times x=40\times (100+x)[/tex]
[tex]x=60ml[/tex]
Thus 60 ml of the 65% mixture will you need to add to obtain the desired solution.
Consider the decomposition of the compound C5H6O3 as follows below. C5H6O3(g) → C2H6(g) + 3 CO(g) When a 5.63-g sample of pure C5H6O3(g) was sealed into an otherwise empty 2.50 L flask and heated to 200.°C, the pressure in the flask gradually rose to 1.63 atm and remained at that value. Calculate K for this reaction.
Answer:
K = 6.5 × 10⁻⁶
Explanation:
C₅H₆O₃(g) → C₂H₆(g) + 3 CO(g)
The formula for the ideal gas law
PV = nRT
where
P = total pressure
V = volume
n = total moles
R = gas constant
T = absolute temperature
P(C₅H₆O₃) = nRT/V
where
n = 5.63 /114
= 0.049
[tex]= \frac{0.049 * 0.0821 * 473}{2.5}[/tex]
= [tex]0.78atm[/tex]
C₅H₆O₃(g) ⇄ C₂H₆(g) + 3 CO(g)
0.78atm 0 0
0.78 - x x 3x
P(total) = 1.63atm
0.78atm - x + x + 3x⇒x = 0.288atm
P(C₅H₆O₃) = 0.78 - 0.288
= 0.489 atm
P(C₂H₆) = 0.288 atm
P(CO) = 0.846 atm
[tex]Kp = \frac{0.288 * 0.864^3}{0.489}[/tex]
= 0.379
K = Kp/(RT³)
[tex]= \frac{0.379}{(0.0821 * 473)^3} \\= 6.5 * 10^-^6[/tex]
K = 6.5 × 10⁻⁶
The value of K for this reaction is : 6.5 * 10⁻⁶
The decomposition equation
C₅H₆O₃ ----> C₂H₆ (g) + 3 CO (g)
Given data :
mass of pure C₅H₆O₃ = 5.63 g
volume of flask = 2.50 L
Temperature = 200°C = 473 K
Pressure in flask = 1.63 atm
Determine the value of K for this reactionwe will apply Ideal gas law formula
PV = nRT
therefore P( C₅H₆O₃ ) = nRT / V ---- ( 1 )
where : n = 5.63 / 114 = 0.049, V = 2.5 L, R = 0.0821, T = 473 k
Insert values into equation ( 1 )
P( C₅H₆O₃ ) = 0.78 atm - x ---- ( 2 )
P(total) = 1.63 atm.
Considering the decomposition equation
0.78 - x + x + 3x = 1.63 atm
therefore ; x = 0.288
back to equation ( 2 )
P( C₅H₆O₃ ) = 0.78 - 0.288 = 0.489 atm
Given that :
P(C₂H₆) = 0.288 atm
P(CO) = 0.846 atm
Find K using the relationship below
K = Kp / ( RT)³ ------ ( 3 )
While Kp = ( 0.288 * 0.864³ ) / 0.489
= 0.379
Back to equation ( 3 )
K = 0.379 / ( 0.0821 * 473 )³
= 6.5 × 10⁻⁶.
Hence we can conclude that the value of K for this reaction is : 6.5 * 10⁻⁶
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You are troubleshooting an older laptop with a thin-film-transistor liquid-crystal display (LCD TFT) screen that is very dim and flickering. You have determined that the LCD graphics adapter is installed and is functioning properly. What is most likely the problem?
Answer:
the inverter has failed
Explanation:
Based on the information provided within the question it can be said that the most likely problem with the LCD screen in this scenario is that the inverter has failed. The inverter is a component used in LCD displays which prepares the power connection so that is provides the correct power to the screens back-light lamp. If there is a problem with the inverter then it would fail to provide enough power which will cause the light and screen to flicker. Such as in this scenario.
The percentage of water vapor present in the air compared to that required for saturation is the ____. a. mixing ratio b. relative humidity c. dew point d. absolute humidity
Answer:
B. Relative Humidity
The maximum number of electrons that are possible at a given energy level depends on the number of ____ at the energy level.
Answer:
orbitalsExplanation:
Each orbital may contain a maximum of two electrons.
The energy level is the principal quantum number: 1, 2, 3, 4, 5, 6, 7.
The principal quantum number limits the kind of orbital (ℓ ) and the number of orbitals (mℓ ).
I. Principal quantum number, n = 1
Angular or orbital quantum number : ℓ = 0 ⇒ ortibal s
Magnetic quantum number: mℓ = 0
⇒ number of orbitals 1 ⇒ number of electrons: 2
II. Principal quantun number, n = 2
Angular or orbital quantum number : ℓ = 0 and 1 ⇒ ortibal s and p
Magnetic quantum number:
for ℓ: mℓ = 0: 1 s ortibal
for ℓ = 1: mℓ = -1, 0, and +1: 3 p ortitals
⇒ number of orbitals 4 ⇒ number of electrons: 8
III. Principal quantun number, n = 3
Angular or orbital quantum number : ℓ = 0, 1, and 2 ⇒ ortibal s, p and d
Magnetic quantum number:
for ℓ: mℓ = 0: 1 s ortibal
for ℓ = 1: mℓ = -1, 0, and +1: 3 p ortitals
for ℓ = 2: mℓ = -2, -1, 0, +1, and +2: 5 d ortitals
⇒ number of orbitals 9 ⇒ number of electrons: 18
IV. Principal quantun number, n = 4
Angular or orbital quantum number : ℓ = 0, 1, 2, and 3 ⇒ ortibal s, p, d and f
Magnetic quantum number:
for ℓ: mℓ = 0: 1 s ortibal
for ℓ = 1: mℓ = -1, 0, and +1: 3 p ortitals
for ℓ = 2: mℓ = -2, -1, 0, +1, and +2: 5 d ortitals
for ℓ = 3: mℓ = ±3, ±2, ±1, and 0: 7 f ortitals
⇒ number of orbitals 16 ⇒ number of electrons: 32.
Thus, you have:
energy level, n maximum number of maximum number of
orbitals electrons
1 1 2
2 4 8
3 9 18
4 16 32
Those numbers follow a rule: n² and 2n². You can verify that the previous numbers are in accordance with those formulas.
Consider a cup of coffee that has a temperature of 93 oC. Assume the mass of the coffee is 550 g and that the specific heat of coffee is about the same as the specific heat of the water. Is a 230 g ice cube (at 0 oC) a large enough ice cube to bring the temperature of the coffee to 23 oC?
Answer:
The answer to your question is No, is not enough
Explanation:
I attached the problem because it says that my answer has bad words.
Suppose paper pulp mills are permitted to emit harmful pollutants, free of charge, into the air. How will the price and output of paper in a competitive market compare with their values under conditions of ideal economic efficiency
Answer:
The price will be too low, and the output will be too large.
Explanation:
Give the stoichiometric coefficient for oxygen when the following equation is balanced using the lowest, whole-number coefficients: ___CH4O(l) ___O2(g) -> ___CO2(g) ____H2O(l)
Answer: [tex]2 \cdot CH_{4} O (l)+3 \cdot O_{2}(g) \rightharpoonup 2 \cdot CO_{2}(g) + 4 \cdot H_{2}O(l)[/tex]
Explanation:
Let consider that one mole of diatomic oxygen is used. So, the stoichometric can be modelled by using three variables:
[tex]x \cdot CH_{4} O (l)+O_{2}(g) \rightharpoonup y \cdot CO_{2}(g) + z \cdot H_{2}O(l)[/tex]
Where [tex]x,y,z[/tex] are the required variables.
Now, three equations are constructed from the number of elements involved (Carbon, Hydrogen and Oxygen):
Carbon
[tex]x=y[/tex]
Oxygen
[tex]x+2=2\cdot y + z[/tex]
Hydrogen
[tex]4\cdot x = 2 \cdot z[/tex]
The coefficients can be found by solving the abovementioned 3 x 3 Linear System:
[tex]x = \frac{2}{3}, y = \frac{2}{3}, z = \frac{4}{3}[/tex]
The whole-number coefficients are determined by multiplying every coefficient by 3, then:
[tex]2 \cdot CH_{4} O (l)+3 \cdot O_{2}(g) \rightharpoonup 2 \cdot CO_{2}(g) + 4 \cdot H_{2}O(l)[/tex]
The stoichiometric coefficient for oxygen in the balanced chemical equation for the combustion of methanol (CH4O) is 2, as it takes two molecules of O2 to provide enough oxygen atoms to form one molecule of CO2 and two molecules of H2O.
Explanation:The stoichiometric coefficient of oxygen (O2) when the equation involving CH4O (methanol) combusting to form CO2 (carbon dioxide) and H2O (water) is balanced, can be determined through following a step-by-step approach:
First, write the unbalanced chemical equation: CH4O(l) + O2(g) -> CO2(g) + H2O(l).Balance carbon (C) atoms by ensuring there is one CO2 molecule for every CH4O molecule.Balance hydrogen (H) atoms by ensuring there are two H2O molecules since there are four hydrogen atoms in CH4O.Finally, balance oxygen atoms. There are two oxygen atoms in CO2 and two more in the two H2O molecules, making four oxygen atoms in the products. Thus, we need two O2 molecules to provide the four oxygen atoms, giving us a coefficient of 2 for O2.The balanced equation is therefore CH4O(l) + 2 O2(g) -> CO2(g) + 2 H2O(l). The stoichiometric coefficient for oxygen is 2.
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H2SO4 + Ba(OH)2à BaSO4 + H2O is an unbalanced chemical equation. What is the coefficient for water when this equation is balanced?
A.1
B.2
C.3
D.4
Answer:
2. Option B.
Explanation:
H₂SO₄ + Ba(OH)₂ → BaSO₄ + 2H₂O
You can count 2H in sulfuric acid and 2 H in the barium hyrdoxide, so the coefficient for water must be 2.
You will have 4 H on both sides of the reaction.
Try with the dissociations of each reactant
Sulfuric acid ⇒ H₂SO₄ → 2H⁺ + SO₄⁻²
Barium hydroxide ⇒ Ba(OH)₂ → Ba²⁺ + 2OH⁻
Sulfate anion bonds to barium cation to produce the salt, therefore the 2 protons will bond the 2 hydroxide in order to produce, 2 moles of H₂O
2H⁺ + 2OH⁻ → 2H₂O
Atoms have a tendency to lose, gain, or share electrons such that their results in an octet of electrons. In other words, atoms have a tendency to lose, gain, or share electrons so as to achieve the electronic configuration of the nearest .
Answer: noble gas
Explanation:
Chemical bond is formed between atoms by losing gaining, or sharing electrons.
When the number of electrons and protons differ, it leads to the formation of ionic species. When an atom gains electrons, it will lead to the formation of negatively charged ion known as anion and when an atom looses electrons, it will lead to the formation of positively charged ion known as cation.
The atoms lose , gain or share electrons to achieve nearest noble gas configuration or to get stable.
Example : Sodium (Na) with atomic number 11 loses one electron to form [tex]Na^+[/tex] to get electronic configuration of neon with 1 0 electrons.
The density of potassium, which has the BCC structure, is 0.855 g/cm3. The atomic weight of potassium is 39.09 g/mol. Calculate (a) the lattice parameter; and (b) the atomic radius of potassium
Answer:
lattice parameter = 5.3355x10^-8 cm
atomic radius = 2.3103x10^-8 cm
Explanation:
known data:
p=0.855 g/cm^3
atomic mass = 39.09 g/mol
atoms/cell = 2 atoms
Avogadro number = 6.02x10^23 atom/mol
a) the lattice parameter:
Since potassium has a cubic structure, its volume is equal to:
v = [(atoms/cell)x(atomic mass)/(p)x(Avogadro number)]
substituting values:
v =[(2)x(39.09)/(0.855x6.02x10^23)]=1.5189x10^-22 cm^3
but as the cell volume is
a^3 =v
[tex]a=\sqrt[3]{v}=\sqrt[3]{1.5189x10^{-22} } = 5.3355x10^-8[/tex] cm
for a BCC structure, the atomic radius is equal to
[tex]r=\frac{ax\sqrt{3} }{4}=\frac{5.3355x10^{-8}x\sqrt{3} }{4}=2.3103x10^{-8}cm[/tex]
An industrial chemist studying bleaching and sterilizing prepares several hypochlorite buffers. Find the pH of 0.200 M HClO and 0.200 M NaClO. (Ka for HClO = 2.9 × 10−8)
Answer:
The pH is 7.54
Explanation:
The Henderson - Hasselbalch equation states that for a buffer solution which consists of a weak acid and its conjugate base, the buffer pH is given by:
pH [tex]=pk_{a} +log(\frac{[conjugate base]}{[weakacid]})[/tex]
pkₐ is for the acid
In this case, the buffer hypochlorous acid HClO is a weak acid, and its conjugate base is the hypochlorite anion ClO⁻ is delivered to the solution via sodium hypochlorite NaClO .
NaCIO = 0.200 M
HCIO = 0.200 M
pkₐ = -log₁₀ kₐ = -log₁₀ (2.9 × 10⁻⁸) = 7.54
∴pH = [tex]=7.54 +log\frac{0.2}{0.2}[/tex] = 7.54
A certain amount of chlorine gas was placed inside a cylinder with a movable piston at one end. The initial volume was 3.00 L and the initial pressure of chlorine was 1.85 atm . The piston was pushed down to change the volume to 1.00 L. Calculate the final pressure of the gas if the temperature and number of moles of chlorine remain constant
Answer:
P₂ = 5.55 atm
Explanation:
Mathematically, Boyle's law can be stated as:
[tex]{\displaystyle P\propto {\frac {1}{V}}}[/tex]
Pressure is inversely proportional to the volume
[tex]{\displaystyle PV=k}[/tex] Pressure multiplied by volume equals some constant [tex]{\displaystyle k}[/tex]
where P is the pressure of the gas, V is the volume of the gas, and k is a constant.
The equation states that the product of pressure and volume is a constant for a given mass of confined gas and this holds as long as the temperature is constant. For comparing the same substance under two different sets of conditions, the law can be usefully expressed as:
[tex]{\displaystyle P_{1}V_{1}=P_{2}V_{2}[/tex]
The final pressure of a gas is calculated using Bolyes law formula
that is P1V1 =P2V2
Because the temperature and number of moles remained constant, we can use the formula
P₁V₁=P₂V₂
3.00 L * 1.85 atm = P₂ * 1.00 L
P₂ = 5.55 atm
Suppose a group of volunteers is planning to build a park near a local lake. The lake is known to contain low levels of arsenic (As). Therefore, prior to starting construction, the group decides to measure the current level of arsenic in the lake.A) If a 15.7 cm3 sample of lake water is found to have 164.5 ng As, what is the concentration of arsenic in the sample in parts per billion (ppb), assuming that the density of the lake water is 1.00 g/cm3?
B) Calculate the total mass (in kg) of arsenic in the lake that the company will have to remove if the total volume of water in the lake is 0.710 km3?
C) Based on the company\'s claim and the concentration of arsenic in the lake, how many years will it take to remove all of the arsenic from the lake, assuming that there are always 365 days in a year?
A) 10.75 is the concentration of arsenic in the sample in parts per billion .
B) 7,633.66 kg the total mass of arsenic in the lake that the company have to remove.
C)It will take 1.37 years to remove all of the arsenic from the lake.
Explanation:
A) Mass of arsenic in lake water sample = 164.5 ng
The ppb is the amount of solute (in micrograms) present in kilogram of a solvent. It is also known as parts-per million.
To calculate the ppm of oxygen in sea water, we use the equation:
[tex]\text{ppb}=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 10^9[/tex]
Both the masses are in grams.
We are given:
Mass of arsenic = 164.5 ng = [tex]164.5\times 10^{-9} g[/tex]
[tex]1 ng=10^{-9} g[/tex]
Volume of the sample = V = [tex]15.3 cm^3[/tex]
Density of the lake water sample ,d= [tex]1.00 g/cm^3[/tex]
Mass of sample = M = [tex]d\times V=1.0 g/cm^3\times 15.3 cm^3=15.3 g[/tex]
[tex]ppb=\frac{164.5\times 10^{-9} g}{15.3 g}\times 10^9=10.75[/tex]
10.75 is the concentration of arsenic in the sample in parts per billion.
B)
Mass of arsenic in [tex]1 cm^3[/tex] of lake water = [tex]\frac{164.5\times 10^{-9} g}{15.3}=1.075\times 10^{-8} g[/tex]
Mass of arsenic in [tex]0.710 km^3[/tex] lake water be m.
[tex]1 km^3=10^{15} cm^3[/tex]
Mass of arsenic in [tex]0.710\times 10^{15} cm^3[/tex] lake water :
[tex]m=0.710\times 10^{15}\times 1.075\times 10^{-8} g=7,633,660.130 g[/tex]
1 g = 0.001 kg
7,633,660.130 g = 7,633,660.130 × 0.001 kg=7,633.660130 kg ≈ 7,633.66 kg
7,633.66 kg the total mass of arsenic in the lake that the company have to remove.
C)
Company claims that it takes 2.74 days to remove 41.90 kilogram of arsenic from lake water.
Days required to remove 1 kilogram of arsenic from the lake water :
[tex]\frac{2.74}{41.90} days[/tex]
Then days required to remove 7,633.66 kg of arsenic from the lake water :
[tex]=7,633.66\times \frac{2.74}{41.90} days=499.19 days[/tex]
1 year = 365 days
499.19 days = [tex]\frac{499.19}{365} years = 1.367 years\approx 1.37 years[/tex]
C)
Company claims that it takes 2.74 days to remove 41.90 kilogram of arsenic from lake water.
Days required to remove 1 kilogram of arsenic from the lake water :
[tex]\frac{2.74}{41.90} days[/tex]
Then days required to remove 7,633.66 kg of arsenic from the lake water :
[tex]=7,633.66\times \frac{2.74}{41.90} days=499.19 days[/tex]
1 year = 365 days
499.19 days = [tex]\frac{499.19}{365} years = 1.367 years\approx 1.37 years[/tex]
It will take 1.37 years to remove all of the arsenic from the lake.
The concentration of arsenic in the lake water sample is 10.5 ppb. The total mass of arsenic in the entire lake is 7445 kg. However, the time required to remove all arsenic from the lake cannot be calculated as the daily removal rate is not specified.
Explanation:To compute the concentration of arsenic in the sample in parts per billion (ppb), we first need to convert the mass of arsenic from ng to g. This gives us 164.5 ng x 10^-9 = 1.645 x 10^-7 g. Given that the density of the water is 1 g/cm^3 = 1 g/mL, a sample of 15.7 cm^3 would weigh 15.7 g. so, the concentration in ppb would be: (1.645 x 10^-7 g / 15.7 g) x 10^9 = 10.5 ppb.
Next, to find the total mass of arsenic in the whole lake, first convert the volume of the lake to cm^3. 0.710 km^3 = 0.710 x 10^15 cm^3. Using the concentration we found earlier, the total mass of arsenic (in g and then in kg) is (10.5 ppb x 0.710 x 10^15 g) x 10^-9 = 7445 kg of arsenic.
Finally, the time to remove all of the arsenic will depend on how much arsenic the company can remove per day, which is not mentioned in the problem. Thus, we can't calculate it based on the information given.
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35.0 mL of stock hydrochloric acid solution is added to a 500 mL volumetric flask. A student adds distilled water up to the line. Using a pH meter and logarithms, he finds the molarity of the new solution to be 0.062 M HCl. What is the molarity of the stock solution?
Answer:
Molarity of stock HCl solution is 0.89 M
Explanation:
The given problem can be solved using laws of dilution.
According to laws of dilution- [tex]C_{1}V_{1}=C_{2}V_{2}[/tex]
Where, [tex]C_{1}[/tex] and [tex]C_{2}[/tex] are initial and final concentration of a solution
[tex]V_{1}[/tex] and [tex]V_{2}[/tex] are initial and final volume of a solution
Here, [tex]V_{1}=35.0mL[/tex], [tex]C_{2}=0.062M[/tex] and [tex]V_{2}=500mL[/tex]
So, [tex]C_{1}=\frac{C_{2}V_{2}}{V_{1}}[/tex] = [tex]\frac{(0.062M)\times (500mL)}{35.0mL}[/tex] = 0.89 M
Hence, molarity of stock HCl solution is 0.89 M
Which step in the process of protein synthesis occurs directly after mrna is assembled?
Answer:
Translation
Explanation:
Protein synthesis is the process of production of proteins in in the cells of living organisms. Transcription and Translation are the two main steps in the protein synthesis. The first step is completed in nucleus where mRNA is made using DNA as template. The second step i.e. translation occurs in the cytoplasm with the help of Ribosomes. The mRNA synthesized during transcription is pre-mRNA. After the processing it is assembled as mature RNA. After getting assembled the second step of protein synthesis viz. Translation begins in the cytoplasm.
What will be the equilibrium temperature when a 235 gg block of copper at 255 ∘C∘C is placed in a 155 gg aluminum calorimeter cup containing 875 gg of water at 16.0 ∘C∘C?
Answer:
The answer to the question is
The equilibrium temperature T = 22.016 °C
Explanation:
To solve the question, we note the given variables thus
Mass of copper block =235 grams
Temperature of the copper block = 255 °C
Mass of aluminium calorimeter cup = 155 g
Mass of water in calorimeter cup = 16 °C
Also we note the specific heat capacities of the materials involved in the question
Specific heat capacity of water = 4.186 joule/gram
Specific heat capacity of copper= 0.385 joule/gram
Specific heat capacity of aluminium = 0.900 joule/gram
There for from the first law of thermodynamics, energy is neither created nor destroyed but it changes from one form to another, we have
Heat lost by copper = heat gained by water and the calorimeter cup
Therefore we have
The equation for heat capacity =
mass * specific heat capacity * Temperature change = m·c·ΔT
therefore
m·c·ΔT for copper = m·c·ΔT for aluminium + m·c·ΔT for water
where ΔT on the left of the equation = Initial temperature - final temperature
while on the right ΔT = Final temperature - Initial temperature
and the final temperature in this case = the equilibrium temperature
255*0.385*(255 -T) = 155*0.9*(T-16) +875*4.186*(T-16)
Which gives the equilibrium temperature T = 22.016 °C
The equilibrium temperature when a 235 g copper block at 255 °C is placed in a 155 g aluminum calorimeter cup containing 875 g of water at 16.0 °C can be found by applying conservation of energy. The heat lost by the hot copper block is equal to the heat gained by the water and the aluminum calorimeter. By setting up and solving this equation, we can determine the final equilibrium temperature.
Explanation:In this calorimeter scenario, we have a hot copper block transferring its heat to the colder aluminum calorimeter and the water it contains. As per the law of conservation of energy, the heat lost by the hot copper block will be equal to the heat gained by the water and the aluminum calorimeter. We can express this mathematically as:
(mass of copper)x(specific heat of copper)x(temperature change of copper) = (mass of water)x(specific heat of water)x(temperature change of water) + (mass of aluminum)x(specific heat of aluminum)x(temperature change of aluminum).
Given the specific heat of aluminum is 0.897 J/g °C, water is 4.184 J/g °C and copper is 0.390 J/g °C, we can substitute these values, as well as the rest of given values, into the equation and solve for the common final temperature, which represents the equilibrium temperature.
Learn more about Calorimetry here:https://brainly.com/question/34432277
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What is the concentration of NOBr, if the concentration of NO was measured to be 0.89 M, Br2 was measured to be 0.562 M, and the equilibrium constant, K, is 1.3 × 10-2?
Answer:
0.076M = [NOBr]
Explanation:
For the reaction:
2NO + Br₂ ⇄ 2 NOBr
The equilibirum constant, K, is defined as:
[tex]K = \frac{[NOBr]^2}{[NO]^2[Br_2]}[/tex](1)
Replacing the concentrations and the equilibrium value in (1):
[tex]1.3x10^{-2} = \frac{[NOBr]^2}{[0.89]^2[0.562]}[/tex]
5.79x10⁻³ = [NOBr]²
0.076M = [NOBr]
I hope it helps!
Write the balanced net ionic equation for the reactions that occur when the given aqueous solutions are mixed. Include the physical states. A. silver nitrate, AgNO 3 AgNO3 , and magnesium bromide, MgBr 2 MgBr2 net ionic equation: B. perchloric acid, HClO 4 HClO4 , and potassium hydroxide, KOH KOH net ionic equation: C. ammonium sulfide, ( NH 4 ) 2 S (NH4)2S , and cobalt(II) chloride, CoCl 2 CoCl2 net ionic equation:
Answer : The balanced net ionic equation for the reactions are:
(A) [tex]2Ag^{+}(aq)+2Br^{-}(aq)\rightarrow AgBr(s)[/tex]
(B) [tex]H^{+}(aq)+OH^{-}(aq)\rightarrow H_2O(l)[/tex]
(C) [tex]Co^{2+}(aq)+S^{2-}(aq)\rightarrow CoS(s)[/tex]
Explanation :
Complete ionic equation : In complete ionic equation, all the substance that are strong electrolyte and present in an aqueous are represented in the form of ions.
Net ionic equation : In the net ionic equations, we are not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
Part A :
The balanced molecular equation will be,
[tex]2AgNO_3(aq)+MgBr_2(aq)\rightarrow Mg(NO_3)_2(aq)+2AgBr(s)[/tex]
The complete ionic equation in separated aqueous solution will be,
[tex]2Ag^+(aq)+2NO_3^{-}(aq)+Mg^{2+}(aq)+2Br^{-}(aq)\rightarrow Mg^{2+}(aq)+2NO_3^{-}(aq)+2AgBr(s)[/tex]
In this equation the species [tex]Mg^{2+}\text{ and }NO_3^-[/tex] are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
[tex]2Ag^{+}(aq)+2Br^{-}(aq)\rightarrow AgBr(s)[/tex]
Part B :
The balanced molecular equation will be,
[tex]HClO_4(aq)+KOH(aq)\rightarrow H_2O(l)+KClO_4(aq)[/tex]
The complete ionic equation in separated aqueous solution will be,
[tex]H^+(aq)+ClO_4^{-}(aq)+K^{+}(aq)+OH^{-}(aq)\rightarrow K^{+}(aq)+CLO_4^{-}(aq)+H_2O(l)[/tex]
In this equation the species [tex]K^{+}\text{ and }ClO_4^-[/tex] are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
[tex]H^{+}(aq)+OH^{-}(aq)\rightarrow H_2O(l)[/tex]
Part C :
The balanced molecular equation will be,
[tex](NH_4)_2S(aq)+CoCl_2(aq)\rightarrow 2NH_4Cl(aq)+CoS(s)[/tex]
The complete ionic equation in separated aqueous solution will be,
[tex]2NH_4^+(aq)+S^{2-}(aq)+Co^{2+}(aq)+2Cl^{-}(aq)\rightarrow 2NH_4^{+}(aq)+2Cl^{-}(aq)+CoS(s)[/tex]
In this equation the species [tex]NH_4^{+}\text{ and }Cl^-[/tex] are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
[tex]Co^{2+}(aq)+S^{2-}(aq)\rightarrow CoS(s)[/tex]
Final answer:
The net ionic equations are: 2Ag+ + 2Br- -> 2AgBr(s); H+ + OH- -> H2O(l); Co2+ + S2- -> CoS(s).
Explanation:
The net ionic equation for the reaction between silver nitrate (AgNO3) and magnesium bromide (MgBr2) is:
2Ag+ + 2Br- -> 2AgBr(s)
The net ionic equation for the reaction between perchloric acid (HClO4) and potassium hydroxide (KOH) is:
H+ + OH- -> H2O(l)
The net ionic equation for the reaction between ammonium sulfide ((NH4)2S) and cobalt(II) chloride (CoCl2) is:
Co2+ + S2- -> CoS(s)
"13.136 A pharmaceutical preparation made with ethanol (C2H5OH) is contaminated with methanol (CH3OH). A sample of vapor above the liquid mixture contains a 97/1 mass ratio of C2H5OH to CH3OH. What is the mass ratio of these alcohols in the liquid mixture
Answer:
Mass ratio of ethanol to methanol in the liquid mixture = 202:1
Explanation:
Starting with a basis of 98.0 g
Amount of ethanol vapour in mass = 97 g
Amount of methanol vapour In mass = 1 g
Number of moles = (mass)/(molar mass)
Molar mass of ethanol = 46.07 g/mol
Molar mass of methanol = 32.04 g/mol
Number of moles of ethanol in the vapour = 97/(46.07) = 2.105 moles
Number of moles of methanol in the vapour = 1/(32.04) = 0.0312 mole
But we do know that
(Number of moles in gaseous form) = (number of moles in liquid state) × (Partial pressure).
Partial Pressure of ethanol = 60.5 torr
Partial pressure of methanol = 126.0 torr
(2.105) = (Number of moles of ethanol in the liquid state) × 60.5
number of moles of ethanol in the liquid state = 2.105/60.5 = 0.0348 moles/torr
(0.0312) = (Number of moles of methanol in the liquid state) × 126
number of moles of methanol in the liquid state = 0.0312/126 = 0.000248 moles/torr
We then convert these new number of moles in liquid state into masses
Mass = (Number of moles) × (molar mass)
(Mass of ethanol in the liquid state) = 0.0348 × 46.07 = 1.603 g/torr
(Mass of methanol in the liquid state) = 0.000248 × 32.04 = 0.00795 g/torr
Mass ratio of ethanol to methanol = (1.603/0.00795) = 201.7: 1 ≈ 202:1
The student's question pertains to finding the mass ratio of ethanol and methanol in a liquid mixture based on the mass ratio in the vapor phase using Raoult's law and the known vapor pressures of the alcohols. To answer accurately, additional data on mass or mole fractions is needed.
Explanation:The student's question deals with the calculation of the mass ratio of alcohols, ethanol (C2H5OH) and methanol (CH3OH), in a liquid mixture based on the mass ratio in the vapor phase. To solve this problem, Raoult's law and the given vapor pressures of both alcohols must be used. Raoult's law states that the vapor pressure of a component in a mixture is equal to the mole fraction of the component in the liquid phase times the vapor pressure of the pure component.
With this information, and knowing the vapor pressure of ethanol is 44 torr and that of methanol is 94 torr at the same temperature, we could use the given vapor mass ratio (97/1) to calculate the mole fraction of each component in the vapor phase. Then, apply Raoult's law in reverse to find the mole fractions in the liquid phase, and finally, convert the mole fractions back into a mass ratio. The molecular weight of ethanol (46.07 g/mol) and methanol (32.04 g/mol) are used for this final step.
To proceed with the solution, more data regarding the mass or mole fractions in the liquid or vapor phase would be necessary. Without such data, we cannot fully determine the exact mass ratio in the liquid mixture.
Evidence for the existence of neutrons did not come until many years after the discoveries of the electron and the proton. Give a possible explanation.
As there was no electric charge on neutrons, and they did not get affected by electromagnetic fields.
Explanation:
The functions of the neutron in atoms is:
To hold the nuclei with coulombic repulsion between the protons.
The neutron has no charge on it and hence were not discovered.
Its mass is slightly less than the proton.
It provides stability to the atom.
Lord Chadwick is credited to prove the existence and discovery of neutron.
He proved that the nucleus of the atom has its mass in the centre as neutron+ proton.
He bombarded beryllium with alpha particles, and found high energy radiation.
The neutron was discovered later than the electron and proton due to the difficulty in detecting uncharged particles. It filled a crucial gap in explaining the atomic nucleus's mass and the existence of isotopes, which differ in neutron count but are chemically identical.
Explanation:The discovery of the neutron was a pivotal moment in the history of subatomic physics. Before the neutron's existence was proven, it was known that the nucleus contained most of an atom's mass, but the mass from protons alone was insufficient to account for it entirely. The detection of neutrons, which are uncharged particles, proved to be much more difficult than that of charged particles like electrons and protons. It was only in 1932 that James Chadwick provided evidence of the neutron, which not only filled the mass discrepancy in the atomic nucleus but also explained the existence of isotopes, which are chemically identical but differ in their number of neutrons.
Proposals to explain this discrepancy included particles hidden within the nucleus. An early hypothesis suggested that neutrons might be a composite of a proton and an electron, which would explain its neutral charge. However, deeper investigation into properties such as the neutron's magnetic moment and mass raised questions that ultimately required a new fundamental particle's acknowledgment.
Systematic or Random Error? -This type of error affects overall accuracy but does not necessarily affect precision. This type of error affects precision but does not necessarily affect overall accuracy. This type of error occurs if you use a buret that was calibrated incorrectly when it was made. You can minimize this type of error by taking repeated measurements.
Answer:
This type of error affects overall accuracy but does not necessarily affect precision. - Systematic error
This type of error affects precision but does not necessarily affect overall accuracy. - Random error
This type of error occurs if you use a buret that was calibrated incorrectly when it was made. - Systematic error
You can minimize this type of error by taking repeated measurements. - Random error
Explanation:
Systematic errors are errors that are attributable to instrument being used during measurement or consistent incorrect measurement during a research. They are consistently and repeatedly committed during measurements and therefore affect the overall accuracy of measurements. A person committing systematic error can have precise repeated measurement but will be far from being accurate.
Random errors on the other hand has no pattern and are usually unavoidable because they cannot be predicted. When sufficient replicate measurements are made, such errors are reduced to the barest minimum and usually do not affect the overall accuracy of measurements.
Which aqueous solution of KI freezes at the lowest temperature?
a. 1 mol of KI in 500. g of water
b. 2 mol of KI in 500. g of water
c. 1 mol of KI in 1000. g of water
d. 2 mol of KI in 1000. g of water
Answer:
b. 2 mol of KI in 500. g of water
Explanation:
We have to apply the colligative property of freezing point depression.
The formula is: ΔT = Kf . m . i
As the (Kf . m . i) is higher, then the freezing temperature will be lower.
i refers to the Van't Hoff factor (number of ions dissolved in the solution)
KI → K⁺ + I⁻ (i =2)
Kf is constant so, we have to search for the highest m (molality)
Molality means the moles of solute in 1kg of solvent.
The highest m is option b → 2 mol of KI / 0.5 kg = 4 mol/kg
a. 1 mol of KI / 0.5 kg = 2 mol/kg
c. 1 mol of KI / 1kg = 1 mol/kg
d. 2 mol of KI / 1kg = 2 mol/kg
1000 g = 1kg. In order to determine molality we need to convert the mass (g) of solvent to kg
The balanced chemical equation for the combustion of hexane is:2C6H14(g) + 19O2(g) The balanced chemical equation for the combustion 12CO2(g) + 14H2O(g)Answer the question in Part 1 through Part 3, if the rate of reaction of C6H14 is 1.43 mol L-1s-1. The rate of reaction of C6H14 is the rate of disappeareance of C6H14.1. What was the rate of formation of CO2?2. What was the rate of formation of H2O?3. What is the rate of reaction of O2?
Answer:
The rate of formation of CO2 = 1.43 mol L-1s-1.
The rate of formation of H2O = 1.43 mol L-1s-1.
The rate of reaction of O2 = 1.43 mol L-1s-1.
Explanation:
2C6H14(g) + 19O2(g) -------> 12CO2(g) + 14H2O(g)
The rate of reaction of C6H14 is 1.43 mol L-1s-1.
The rate of reaction is theoretically defined as the speed of a chemical reaction. It is how fast or how slow the reactants are being used up or products are being formed.
It is the rate of change of concentration, amount etc., of any of the reactant or any of the product with time. The rate of reaction is the same and uniform for any of the products and reactants.
For a chemical reaction, A + 2B -----> 2C
r = -(dA/dt) = -(dB/dt) = (dC/dt)
Hence, the rate of reaction = rate of disappearance of C6H14 = rate of formation of CO2 = rate of formation of H2O = rate of reaction of O2 = 1.43 mol L-1s-1.
Hope this Helps!!!
Nitrogen gas is transformed into ammonia C. Ammonification Release of ammonia during decomposition A. Denitrification The conversion of ammonia to nitrate and nitrite B. Nitrificaiton The reduction of nitrate into N2O, NO, and N2 D. Nitrogen fixation
Answer:
D. Nitrogen Fixation
Explanation:
Nitrogen fixation is a process by which molecular nitrogen in the air is converted into ammonia (NH
3) or related nitrogenous compounds in soil.
Zinc reacts with hydrochloric acid according to the reaction equation Zn ( s ) + 2 HCl ( aq ) ⟶ ZnCl 2 ( aq ) + H 2 ( g ) How many milliliters of 5.00 M HCl ( aq ) are required to react with 3.15 g Zn ( s ) ?
Answer:
We need 19.3 mL of HCl
Explanation:
Step 1: Data given
Molarity HCl = 5.00 M
Mass Zn = 3.15 grams
Step 2: The balanced equation
Zn (s) + 2HCl (aq) ⟶ ZnCl2 (aq) + H2 (g)
Step 3: Calculate moles Zn
Moles Zn = mass Zn / molar mass Zn
Moles Zn = 3.15 grams / 65.38 g/mol
Moles Zn = 0.0482 moles
Step 4: Calculate moles HCl needed
For 2 moles HCl we need 1 mol Zn to produce 1 mol ZnCl2 and 1 mol H2
For 0.0482 moles Zn we need 2*0.0482 = 0.0964 moles HCl needed
Step 5: Calculate volume needed
Molarity = moles / volumes
Volumes = moles / molarity
Volume HCl needed = 0.0964 moles HCl /5.00 M
Volume HCl needed = 0.01928 L = 19.3 mL
We need 19.3 mL of HCl
A sample of nitrogen goes from 21L to 14L and it's pressure increases from 100kPa to 150kPa. The final temperature is 300K. What was the initial temperature in Kelvins?
Answer:
The initial temperature is 300 K (The temperature doesn't change)
Explanation:
Step 1: Data given
Initial volume = 21L
Final volume = 14L
Initial pressure = 100 kPa = 0.986923 atm
Final pressure = 150 kPa = 1.48038 atm
The final temperature = 300K
Step 2: Calculate the initial temperature
Calculate the initial temperature
(P1*V1)/T1 = (P2*V2)/T2
⇒with P1 = the initial pressure = 0.986923 atm
⇒with V1 = the initial volume = 21 L
⇒ with T1 = the initial temperature = ?
⇒with P2 = the final pressure = 1.48038 atm
⇒with V2 = the final volume = 14 L
⇒with T2 = the final temperature = 300 K
(0.986923 * 21)/T1 = (1.48038*14)/300
T1 = 300 K
The initial temperature is 300 K (The temperature doesn't change)