Answer:
The answer is B (sodium is more reactive)
Explanation:
The lesser reactive element to magnesium is present on the left side of the magnesium in the periodic table in the same row. Thus, option B is correct.
What is a periodic table?The periodic table is given as the arrangement of the elements in columns and rows based on the increasing order of the atomic number and the number of valence electrons.
In a periodic table, on moving from left to right reactivity increases, and from top to bottom reactivity decreases.
Thus, the element with the lesser reactivity than magnesium is present in the left of the magnesium in the same row. Thus, option B is correct.
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You start with 0.050 moles of ammonia in 500. mL of water. The equilibrium constant Keq is 1.8 × 10–5. What is the pH of this solution at equilibrium? Please show work!
Answer:
[tex]\boxed{11.13}[/tex]
Explanation:
The chemical equation is
[tex]\rm NH$_{3}$ + \text{H}$_{2}$O \, \rightleftharpoons \,$ NH$_{4}^{+}$ +\text{OH}$^{-}$[/tex]
For simplicity, let's rewrite this as
[tex]\rm B + H$_{2}$O \, \rightleftharpoons\,$ BH$^{+}$ + OH$^{-}$[/tex]
1. Initial concentration of NH₃
[tex]\text{[B]} = \dfrac{\text{moles}}{\text{litres}} = \dfrac{\text{0.050 mol}}{\text{0.500 L}} = \text{0.100 mol/L}[/tex]
2. Calculate [OH]⁻
We can use an ICE table to do the calculation.
B + H₂O ⇌ BH⁺ + OH⁻
I/mol·L⁻¹: 0.100 0 0
C/mol·L⁻¹: -x +x +x
E/mol·L⁻¹: 0.100 - x x x
[tex]K_{\text{b}} = \dfrac{\text{[BH}^{+}]\text{[OH}^{-}]}{\text{[B]}} = 1.8 \times 10^{-5}\\\\\dfrac{x^{2}}{0.100 - x} = 1.8 \times 10^{-5}[/tex]
Check for negligibility:
\[tex]\dfrac{0.100 }{1.8 \times 10^{-5}} = 5600 > 400\\\\ x \ll 0.100[/tex]
3. Solve for x
[tex]\dfrac{x^{2}}{0.100} = 1.8 \times 10^{-5}\\\\x^{2} = 0.100 \times 1.8 \times 10^{-5}\\\\x^{2} = 1.80 \times 10^{-6}\\\\x = \sqrt{1.80 \times 10^{-6}}\\\\x = \text{[OH]}^{-} = 1.34 \times 10^{-3} \text{ mol/L}[/tex]
4. Calculate the pH
[tex]\text{pOH} = -\log \text{[OH}^{-}] = -\log(1.34 \times 10^{-3}) = 2.87\\\\\text{pH} = 14.00 - \text{pOH} = 14.00 - 2.87 = \mathbf{11.13}\\\\\text{The pH of the solution at equilibrium is } \boxed{\mathbf{11.13}}[/tex]
What is the percent by mass of sodium in Na2SO4?
Answer:
= 32.39 %
Explanation:
The relative atomic mass of sodium is 23, sulphur 32 while oxygen as a relative atomic mass of 16.
I mole of Na₂SO₄ has a relative mass of 2(23) + 32 + 4(16) = 142 grams
Of the value 142, the contribution of sodium is 2×23 =46
Thus the % composition is calculated:
46/142×100%= 32.39%
BRAINIEST AND MAX POINTS
The diagram below shows four processes, A, B, C, and D, by which carbon circulates between the atmosphere, plants, and animals.
Which processes represent respiration?
Process A and Process C
Process B and Process D
Process A and Process D
Process B and Process C
Answer:
precess a and b
Explanation:
Answer: I believe the answer is A) Process A and Process C !!!!!!!!
How are nuclear reactions different from chemical reactions?
Select all that apply.
In nuclear reactions, the identities of the elements change.
In nuclear reactions, the identities of the elements stay the same.
In nuclear reactions, the reactions happen at a set rate.
In nuclear reactions, the reactions happen at a varied rate.
Explanation:
Nuclear reactions are defined as the reaction in which there occurs change in the nucleus of an atom due to change in number of protons or neutrons of an atom.
For example, [tex]^{2}_{1}H + ^{2}_{1} \rightarrow ^{4}_{2}He[/tex] is a nuclear reaction.
Hence, identity of the element changes in a nuclear reaction. Also, nuclear reaction can occur at varied rates as they are not affected by temperature, pressure or catalyst.
Whereas a chemical reaction is defined as the reaction where there occurs exchange of electrons between the combining atoms.
For example, [tex]2Na(s) + Cl_{2}(g) \rightarrow 2NaCl[/tex] is a chemical change.
Thus, we can conclude that nuclear reactions are different from chemical reactions as follows.
In nuclear reactions, the identities of the elements change.In nuclear reactions, the reactions happen at a varied rate.WILL MARK BRAINLIEST ASAP 20 POINTS
Answer:
elta H = Potential Energy of the Products - Potential Energy of the Reactants.
This would be C-A = delta H
The activation energy would be B-A
This is the energy necessary to start the reaction
Answer:
its the relationship between energies and the coeficcients on the graph.
Explanation:
0.0006510 kg has
how many significant figures.
Answer:
4 significant figures as zeros after decimal should not be counted
Explanation:
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Answer:
4 significant figures
DDT is made from the __ of unsaturated hydrocarbons
Answer:
chlorination
Explanation:
Answer: chlorination
Explanation: DDT is made from the
of unsaturated hydrocarbons.
The rock in a lead ore deposit contains 89 % PbS by mass. How many kilograms of the rock must be processed to obtain 1.5 kg of Pb?
Answer:
Approximately 1.9 kilograms of this rock.
Explanation:
Relative atomic mass data from a modern periodic table:
Pb: 207.2;S: 32.06.To answer this question, start by finding the mass of Pb in each kilogram of this rock.
89% of the rock is [tex]\rm PbS[/tex]. There will be 890 grams of [tex]\rm PbS[/tex] in one kilogram of this rock.
Formula mass of [tex]\rm PbS[/tex]:
[tex]M(\mathrm{PbS}) = 207.2 + 32.06 = 239.26\; g\cdot mol^{-1}[/tex].
How many moles of [tex]\rm PbS[/tex] formula units in that 890 grams of [tex]\rm PbS[/tex]?
[tex]\displaystyle n = \frac{m}{M} = \rm \frac{890}{239.26} = 3.71980\; mol[/tex].
There's one mole of [tex]\rm Pb[/tex] in each mole of [tex]\rm PbS[/tex]. There are thus [tex]\rm 3.71980\; mol[/tex] of [tex]\rm Pb[/tex] in one kilogram of this rock.
What will be the mass of that [tex]\rm 3.71980\; mol[/tex] of [tex]\rm Pb[/tex]?
[tex]m(\mathrm{Pb}) = n(\mathrm{Pb}) \cdot M(\mathrm{Pb}) = \rm 3.71980 \times 207.2 = 770.743\; g = 0.770743\; kg[/tex].
In other words, the [tex]\rm PbS[/tex] in 1 kilogram of this rock contains [tex]\rm 0.770743\; kg[/tex] of lead [tex]\rm Pb[/tex].
How many kilograms of the rock will contain enough [tex]\rm PbS[/tex] to provide 1.5 kilogram of [tex]\rm Pb[/tex]?
[tex]\displaystyle \frac{1.5}{0.770743} \approx \rm 1.9\; kg[/tex].
How many grams of aluminum are in 0.58 moles of Al2O3.2H:0?
Answer:
80.04 gram
Explanation:
mass = moles × relative formula mass
= 0.58×138
= 80.04
Which of the following best describes hail?
A- Small ice pellets that may fall to the ground in a mixture of rain and snow in the form of a solid
B- A form of precipitation that occurs when liquid and frozen precipitation freezes in layers creating chunks
C- Water droplets that collide with others to form large drops as they leave the clouds and fall toward the ground
D- Solid precipitation that is formed in clouds as ice crystals that stick together in groups to form flakes and leave the clouds as flakes
Answer:
A- Small ice pellets that may fall to the ground in a mixture of rain and snow in the form of a solid
Explanation:
Small ice pellets that may fall to the ground in a mixture of rain and snow in the form of a solid best describes hail.
Small ice pellets that may fall to the ground in a mixture of rain and snow in the form of a solid describe Hail.
What is Hail?Hail is a form of precipitation, or water that can easily fall to the ground from the atmosphere. Hail is former when water droplets freeze together in the clouds. The ice that formed are called hailstones.
Hailstones length is between 5 millimeters and 15 centimeters
Therefore, Small ice pellets that may fall to the ground in a mixture of rain and snow in the form of a solid describe Hail.
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HELP NEED HELP PLEASE !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer: B) 4.2 M
Explanation:
Molarity = moles of solute/litre of solution
1560mL/1000 = 1.56 litres
6.5/1.56 = x/1
x = 4.2
M of solution = 4.2
what does the capital letter, such as T, represent in a punnett square
Answer: A dominant gene.
Explanation:
Answer:
The dominant form of a gene
Explanation:
The capital letter, such as T, represents the dominant form of a gene in a punnett square.
Why does liquid water have such a high heat capacity?
Choose 1 answer:
Choose 1 answer:
(Choice A)
A
Water is a nonpolar molecule.
(Choice B)
B
Water molecules are good at forming and breaking hydrogen bonds.
(Choice C)
C
Water molecules are packed very closely together.
(Choice D)
D
Water is a linear molecule which makes absorbing heat easier.
Answer:
B
Explanation:
Water molecules are good at forming and breaking hydrogen bonds.
The breaking and reforming of hydrogen bonds in liquid water can absorb a large amount of heat, making water resistant to temperature change.
A potential energy diagram is shown.
What is the activation energy of this reaction?
Answer:
Ea = 35 kJ.
Explanation:
Activation energy (Ea) is the difference between the potential energy of intermediate "activated complex/ peak" and reactants.
Ea = P.E. of products - P.E. of reactants = 65 kJ - 30 kJ = 35 kJ.
kindly find the attached image.
According to Boyle's law, what would happen to the temperature of a gas if the pressure were halved as the number of moles and the volume were held constant?
A.The temperature would double.
B.The temperature would be reduced by half.
C.The temperature would quadruple.
D.The temperature would be one-quarter of its original value.
According to Boyle's law, the temperature would double of a gas if the pressure were halved as the number of moles and the volume were held constant. Hence, option A is correct.
What is Boyle's law?Boyle's law states that at constant temperature, the pressure exerted by a gas is inversely proportional to the volume occupied by it.
If temperature is held constant, the equation is reduced to Boyle's law. Therefore, if you decrease the pressure (P↓) of a fixed amount of gas, its volume (v ↑) will increase.
(P↓) → (v ↑)
P∝ [tex]\frac{1}{V}[/tex]
However, if you were to maintain a constant volume while decreasing pressure, the temperature would also have to decrease.
Thus, according to Boyle's law, the temperature would double of a gas if the pressure were halved as the number of moles and the volume were held constant.
Hence, option A is correct.
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QUICK PLEASE HELP!!!during a combustion reaction, 5.00 grams of oxygen reacted with 5.00 grams of CH4.
What is the amount of the leftover reactant?
4.00 grams of methane
3.75 grams of methane
2.75 grams of oxygen
1.75 grams of oxygen
To determine the leftover reactant in the combustion of 5.00 grams of oxygen and 5.00 grams of CH4, the limiting reagent calculation shows that the leftover reactant is 3.75 grams of methane as oxygen is the limiting reagent.
Explanation:To determine the amount of the leftover reactant in a combustion reaction involving 5.00 grams of oxygen and 5.00 grams of CH4, we need to conduct a limiting reagent calculation. The balanced chemical equation for the combustion of methane (CH4) is:
CH4(g) + 2O2(g) → CO2(g) + 2H2O(l)
From the balanced equation, we can see that one mole of CH4 reacts with two moles of O2. The molar mass of CH4 is 16.04 g/mol, and the molar mass of O2 is 32.00 g/mol, so we can use these to convert the mass of each reactant to moles:
For 5.00 g of CH4: 5.00 g / 16.04 g/mol = 0.3117 mol CH4For 5.00 g of O2: 5.00 g / 32.00 g/mol = 0.15625 mol O2Since the reaction requires 2 moles of O2 for each mole of CH4, we can calculate the needed moles of O2 for the reaction with the available CH4:
0.3117 mol CH4 × 2 mol O2 / 1 mol CH4 = 0.6234 mol O2 needed
However, we only have 0.15625 mol of O2 available, which is less than 0.6234 mol. This means O2 is the limiting reagent, and there will be some unreacted CH4 left over. Since all of the oxygen will be used up, we can calculate the leftover mass of methane:
0.15625 mol O2 × 1 mol CH4 / 2 mol O2 = 0.078125 mol CH4 reacted
0.3117 mol CH4 - 0.078125 mol CH4 reacted = 0.233575 mol CH4 unreacted
Finally, we convert the moles of unreacted CH4 back to grams:
0.233575 mol CH4 × 16.04 g/mol = 3.75 grams of CH4
Therefore, the amount of the leftover reactant is 3.75 grams of methane.
what is the wavelength of a 3*10^12 Hz infrared wave
A 3*10^20m
B 1* 10^4m
C 3*10^-3m
D 1*10^-4 m
Answer:
D. 1 × 10⁻⁴ m
Explanation:
Electromagnetic waves travel through space with the speed of light which is approximately 3.0 ×10⁻⁸ m/s.
The speed is calculated as follows:
c=λf
Where λ is the wavelength of the wave, f the frequency and c the speed of light.
Thus λ=c/f
=(3×10⁸ m/s) / (3×10¹²Hz)
Wavelength, λ= 1 × 10⁻⁴ m
Answer:
D
Explanation:
A.P.E.X.
Homologous chromosomes pair up during what phase of meiosis:
Answer:
prophase I
Explanation:
Homologous chromosomes pair up during prophase I of meiosis.
The following chemical equation is not balanced.
Ca + AIPO4 — Al + Caz(PO4)2
When the equation is balanced, what is the coefficient for pure aluminum
(AI)?
A) 1
B) 2
C) 4
D 8
Answer:
3Ca + 2AlPO4 = Ca3(PO4)2 + 2Al.
That is B
Answer:
The stoichiometric coefficient of aluminium is 2 that is option B is correct.
Explanation:
Stoichiometric coefficient is the numeral coming or written before the symbol of compound or an element in balanced chemical reaction equation.
[tex]3Ca + 2AIPO_4 \rightarrow 2Al + Ca_3(PO_4)_2[/tex]
According to stoichiometry, 3 moles of calcium reacts with 2 moles of aluminum phosphate to give 2 moles of aluminium and 1 mole of calcium phosphate.
The stoichiometric coefficient of calcium is = 3
The stoichiometric coefficient of aluminum phosphate = 3
The stoichiometric coefficient of aluminium = 2
The stoichiometric coefficient of calcium phosphate = 1
molar mass of fe2o3 g/mol
Answer:
159.7
Explanation:
hope this helps
Which of the following is a sign a chemical reaction has occurred?
Answer:
2. A piece of metal is placed in water and produces sparks and gas
Explanation:
The production of gas is usually a sign of a chemical reaction. The metal is reacting with the water to form a new substance (the gas).
Incorrect answers and why:
1. Changing colors can be a sign of a chemical reaction, but in this case it's more likely that the colors blended together. (If it was something like two clear liquids combining to form a yellow liquid, then it would be more clear evidence of a chemical reaction)
3. The liquid is boiling
4. The powder dissolved into the liquid
I hope this helps!
The statement that is a sign a chemical reaction has occurred is a piece of metal is placed in water and produces sparks and gas. The correct option is b.
What is a chemical reaction?A chemical reaction is a process in which two or more substances called reactants react to form a different substance or compound, called a product. The metal reacts with water and forms gas and sparks in a chemical reaction.
Although a chemical reaction might cause colors to change, in this case, it's more likely that the hues just mixed. (If it involved the blending of two clear liquids to create a yellow liquid, that would be more convincing proof of a chemical reaction.)
Thus, the correct option is b. A piece of metal is placed in water and produces sparks and gas.
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A salad including lettuce, tomatoes, and onions would be classified as a _________.
Answer:
simple salad
Explanation:
Hi.
Anwers : Vegetable salad.
Achievements.
which class of compunds has the general formula r-o-r
Answer:
R-O-R is the general formula for Symmetrical Ethers,in which both alkyl groups attached on oxygen are same .
Explanation:
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Which of the following groups gets energy directly from the grass it eats?
A.producers
B. Decomposers
C.primary consumer
D.secondary consumers
Answer: C. Primary Consumers
Explanation:
Answer:
Primary consumer.
Explanation:
Food chain may be defined as the sequential flow of food energy from one level to the next tropic level. Producers are the first organism that occupies the first tropic level in the food chain.
Producers prepare their food by themselves. Primary consumers get their food by eating directly the producers. Primary consumers are generally feed on the plants and grass.
Thus, the correct answer is option (C).
one or more substances changing into one or more substances is an example of a
Hello There!
This is called a "Chemical Change"
A chemical change is when the composition of a substance changes. There are many signs of chemical changes. When a chemical change occurs, you can see a change in color. When a new color is visible that means that a new substance has been created. There also is a new smell "odor" this hints that a new substance has been formed.
Why does a red shoe appear red in daylight
Answer:
Because it does
Explanation:from sun light DUHHHH
How do limiting factors most affect population size?
O
stop population growth
restrict population growth
increase population size
result in positive impacts
O
Answer:
restrict population growth ( second choice).
Gas particles moving through the air due to random motion is called what??
Answer:
Explanation:
In gases the particles move rapidly in all directions, frequently colliding with each other and the side of the container. With an increase in temperature, the particles gain kinetic energy and move faster. ... In liquids, particles are quite close together and move with random motion throughout the container.
Gas particles moving through the air due to random motion is called Brownian motion.
What is Gas ?Gas have no definite volume and gases have not a definite shape it can take the shape of container in which it filled. Gases can flow easily. They are highly compressible. They have low density. Gases have very weak intermolecular force and very large intermolecular space.
What is Brownian Motion ?Brownian motion is also called as Brownian movement is defied as the zig-zag motion of particles suspended in a medium. The gas particles moves randomly in Brownian motion.
Thus from the above conclusion we can say that Gas particles moving through the air due to random motion is called Brownian motion.
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Complete the table for ion charge based upon their losing or gaining electrons in the outer shell. (Use the periodic table as necessary.) Group Most Likely Ionic Charge # of Valence Electrons I +1 II +2 III +3 IV +4 or -4 V -3 VI -2 VII -1 VIII 0
Answer:
Explanation:
Group Most Likely Ionic Charge Number of Valence Electrons
I +1 1
II +2 2
III +3 3
IV +4 or -4 4
V -3 5
VI -2 6
VII -1 7
VIII 0 8
For elements in group IV and above, their ionic charge is (8-number of their valence electrons.)
Explanation:
Valence electrons are defined as the electrons which are present in the outermost shell of an atom.
The number of valence electrons in a particular group will be equal to the group number.
Number of valence electrons = Group number
The given table follows:
Group Most likely ionic charge No. of valence electrons
I +1 1
II +2 2
III +3 3
IV +4 or -4 4
V -3 5
VI -2 6
VII -1 7
VIII 0 8
name 3 cell structures that are found in a plant cell and NOT in an animal cell;
Answer:
cell wall
chloroplasts
central vacuole
Explanation:
Plant cells have a cell wall, chloroplasts, and a central vacuole. These structures are not found in animal cells.
The structures of three cells present in the cells in plant, but not animal cell are Cell wall, Chloroplast and Plastids.
Explanation:Animal cell only contain cell membrane whereas plant cell has both cell wall and cell membrane. Unlike animal cell, plant cell makes their own food. The plants come under autotrophs and animals come under heterotrophs.
For this purpose, there is chloroplast in a plant cell. The major function of chloroplast is to produce food through photosynthesis. Plastids are the pigment containing cell organelles which is responsible for the color of plant cell.