Explanation:
An exothermic reaction is a chemical reaction that during the chemical reaction releases energy. "Exo" means releases under the word Exothermic and "thermic" means heat. Bonds are broken and replaced as chemical reactions occur, forming new materials. When bonds are formed energy is released and for breaking of the bond, energy is needed. Hence, when weak bonds are broken less amount of energy is needed and when a strong bond is formed a high amount of energy is released.In Keynes's liquidity preference framework, as the expected return on bonds increases (holding everything else unchanged), the expected return on money ________, causing the demand for ________ to fall.
Answer:
the correct words to fill up the blank spaces are falls and money
Explanation:
.1. the expected return on money falls
.2. causing the demand for money to fall.
The ph of 0.010 m aqueous aniline is 8.32. What is the percentage protonated?
Answer : The percentage aniline protonated is, 0.0209 %
Explanation :
First we have to calculate the pOH.
[tex]pH+pOH=14\\\\pOH=14-pH\\\\pOH=14-8.32\\\\pOH=5.68[/tex]
Now we have to calculate the hydroxide ion concentration.
[tex]pOH=-\log [OH^-][/tex]
[tex]5.68=-\log [OH^-][/tex]
[tex][OH^-]=2.09\times 10^{-6}M[/tex]
The equilibrium chemical reaction will be:
[tex]NH_3+H_2O\rightleftharpoons NH_4^++OH^-[/tex]
From the reaction we conclude that,
Concentration of [tex]OH^-[/tex] ion = Concentration of [tex]NH_4^+[/tex] ion = [tex]2.09\times 10^{-6}M[/tex]
Now we have to calculate the percentage aniline protonated.
[tex]\text{percentage aniline protonated}=\frac{2.09\times 10^{-6}M}{0.010M}\times 100[/tex]
[tex]\text{percentage aniline protonated}=0.0209\%[/tex]
Thus, the percentage aniline protonated is, 0.0209 %
Which planets are composed more of gas than liquids and solids? A. Venus, Jupiter, Neptune, and Mercury B. Jupiter, Saturn, Uranus, and Neptune C. Venus, Jupiter, Uranus, and Neptune D. Jupiter, Saturn, Neptune, and Mercury
Answer:
the answer is b :)
Explanation:
Answer: B
Explanation:
I just had this question on Study Island.
NH4CO2NH2(s) equilibrium reaction arrow 2 NH3(g) + CO2(g) Ammonium carbamate decomposes according to the equation above. At 40°C, an equilibrium mixture for this reaction contains 0.0640 atm CO2 and 0.370 atm NH3. What is the value of the equilibrium constant Kp for the reaction?
Answer:
Kp = 8.76×10⁻³
Explanation:
We determine the carbamate decomposition in equilibrium:
NH₄CO₂NH₂ (s) ⇄ 2NH₃(g) + CO₂(g)
Let's build the expression for Kp
Kp = (Partial pressure NH₃)² . Partial pressure CO₂
We do not consider, the carbamate because it is solid and we only need the partial pressure from gases
Kp = (0.370atm)² . 0.0640 atm
Kp = 8.76×10⁻³
Remember Kp does not carry units
The value of the equilibrium constant Kp for the decomposition of ammonium carbamate at 40°C, given the partial pressures of 0.370 atm for NH3 and 0.0640 atm for CO2, is 0.0087616.
The decomposition of ammonium carbamate to ammonia and carbon dioxide at equilibrium can be represented by the following equation:
NH4CO2NH2(s) ⇌ 2 NH3(g) + CO2(g)
The equilibrium constant for a reaction involving gases, Kp, is based on the partial pressures of the gaseous products and reactants. The equilibrium constant expression for this reaction is:
Kp = (PNH3)^2 × (PCO2)
Given the equilibrium partial pressures, 0.370 atm of NH3 and 0.0640 atm of CO2, we can calculate the Kp value:
Kp = (0.370)^2 × (0.0640) = 0.1369 × 0.0640 = 0.0087616
So, the value of the equilibrium constant Kp for the reaction at 40°C is 0.0087616.
To find the percent by mass of a compound if you are given the formula, divide the molar mass of that element in one mole of the compound by the total molar mass of the compound, multiplied by 100.
Final answer:
To calculate the percent by mass of each element in a compound, divide the mass of each element in one mole by the total molar mass of the compound and multiply by 100. The sum of the percentages for all elements should equal 100% for a pure compound.
Explanation:
To determine the percent by mass of each element in a compound, one needs to carry out a series of calculations. First, you should find the mass of each element in one mole of the compound by using the compound's chemical formula and the atomic masses of the elements (this can be found on the periodic table). Then, divide this mass by the compound's molar mass (which is the sum of all the atomic masses from the chemical formula) and multiply the result by 100 to get the percentage. The sum of these percentages for all elements in the compound should be 100%, assuming the compound is pure.
True.
The percent by mass of an element in a compound can be calculated by dividing the molar mass of that element by the total molar mass of the compound and then multiplying by 100 to express it as a percentage. This calculation gives the proportion of the compound's mass that is attributed to a specific element.
True. To find the percent by mass of an element in a compound, you can use the formula:
[tex]\[ \text{Percent by Mass} = \left( \frac{\text{Molar Mass of Element}}{\text{Total Molar Mass of Compound}} \right) \times 100 \][/tex]
Here's how it works: For each element in the compound, calculate its molar mass (the mass of one mole of atoms of that element). Then, add up the molar masses of all the elements in the compound to find the total molar mass of the compound. Finally, apply the formula by taking the molar mass of the specific element and dividing it by the total molar mass of the compound. Multiply the result by 100 to express the ratio as a percentage. This calculation helps determine the relative abundance of each element in the compound based on their masses.
The probable question may be:
To find the percent by mass of a compound if you are given the formula, divide the molar mass of that element in one mole of the compound by the total molar mass of the compound, multiplied by 100.
True/False.
Boyle's law states that gas volume is Boyle's law states that gas volume is inversely proportional to temperature. directly proportional to pressure. inversely proportional to pressure. directly proportional to temperature. both directly proportional to pressure and directly proportional to temperature.
Answer: Boyle's law states that gas volume is inversely proportional to pressure.
Explanation:
Boyle's law is one of the law used to determine the Ideal Gas equation.
This law states that pressure of the gas is inversely proportional to the volume of the gas at constant temperature and number of moles
Mathematically,
[tex]P\propto \frac{1}{V}[/tex] (at constant temperature and number of moles)
The above expression can also be written as:
[tex]P_1V_1=P_2V_2[/tex]
where,
[tex]P_1\text{ and }V_1[/tex] are initial pressure and volume of the gas
[tex]P_2\text{ and }V_2[/tex] are final pressure and volume of the gas
Hence, Boyle's law states that gas volume is inversely proportional to pressure.
Boyle's law states that at constant temperature, the volume of a fixed amount of gas is inversely proportional to its pressure. Thus, if the pressure on a gas increases, its volume decreases, and vice versa. This relationship is crucial for understanding gas behavior.
Boyle's law states that the volume of a given amount of gas held at constant temperature is inversely proportional to the pressure under which it is measured. This means if the pressure on a gas increases, its volume decreases, as long as the temperature and the amount of gas remain constant, and vice versa.
If we express this relationship mathematically:
V ∝ 1/P or PV = k (where k is a constant)
For example, if you double the pressure on a gas, its volume will decrease by half, provided the temperature stays the same. This principle is essential in understanding the behavior of gases in various conditions.
Which compounds will be soluble in water?
Answer:
salt
Explanation:
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?
Answer:
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]
It will take 1.37 years to remove all of the arsenic from the lake.
The decay series for 238 92U is represented in Figure 19.1. Write the balanced nuclear equation for each of the following radioactive decays. a. Alpha-particle production by 226 88 Ra b. Beta-particle production by 214 82 Pb
Answer: The decay process of the radioisotopes are written below.
Explanation:
For the given options:
Option a:Alpha decay is defined as the process in which the nucleus of an atom disintegrates into two particles. The first one which is the alpha particle consists of two protons and two neutrons, also known as helium nucleus. The second particle is the daughter nuclei which is the original nucleus minus the alpha particle released.
[tex]_Z^A\textrm{X}\rightarrow _{Z-2}^{A-4}\textrm{Y}+_2^4\alpha[/tex]
The chemical equation for the alpha decay process of Ra-226 isotope follows:
[tex]_{88}^{226}\textrm{Ra}\rightarrow _{86}^{222}\textrm{Rn}+_2^4\alpha[/tex]
Option b:Beta decay is defined as the process in which the neutrons get converted into an electron and a proton. The released electron is known as the beta particle. In this process, the atomic number of the daughter nuclei gets increased by a factor of 1 but the mass number remains the same.
[tex]_Z^A\textrm{X}\rightarrow _{Z+1}^{A}\textrm{Y}+_{-1}^0\beta[/tex]
The chemical equation for the alpha decay process of Pb-214 isotope follows:
[tex]_{82}^{214}\textrm{Pb}\rightarrow _{83}^{214}\textrm{Bi}+_{-1}^0\beta[/tex]
Hence, the decay process of the radioisotopes are written above.
Mg(OH)2 in the form of Milk of Magnesia is used to neutralize excess stomach acid. Mg(OH)2 58.33 11. How many moles of stomach acid can be neutralized by 1.00 g of Mg(OH)2
Answer:
0.03429 mole
Explanation:
The type of acid present in the stomach is hydrochloric acid (HCl).
From the balanced equation:
[tex]Mg(OH)_2 + 2HCl --> MgCl_2 + 2H_2O[/tex]
2 moles of HCl requires 1 mole of Mg(OH)2 fro complete neutralization.
moles of Mg(OH)2 present in 1g = mass/molar mass
= 1/58.33 = 0.01714 mole
If 1 mole of Mg(OH)2 is needed for 2 moles of HCl, then
0.01714 mole of Mg(OH)2 will require: 2 x 0.01714 moles HCl
= 0.03429 mole of HCl
Hence, 0.03429 mole of stomach acid can be neutralized by 1.00g of Mg(OH)2
At their centers, all the jovian planets have cores made of:
new elements produced by the high pressure; elements which we do not have on Earth
hydrogen and helium in the form of gas
a solid mixture of rocky and icy materials under great pressure
methane, ammonia, and sulfur compounds
hydrogen and helium in the form of liquids
Final answer:
The cores of the Jovian planets are composed of a solid mixture of rocky and icy materials under great pressure, and their compositions are dominated by elements like carbon, nitrogen, and oxygen.
Explanation:
The cores of the jovian planets, such as Jupiter, Saturn, Uranus, and Neptune, are composed of a solid mixture of rocky and icy materials under great pressure.
This information is supported by studies of the gravitational fields of these planets and the fact that their compositions are dominated by elements like carbon, nitrogen, and oxygen, along with rock and ice.
Although the cores exist at pressures of tens of millions of bars, the materials referred to as 'rock' and 'ice' do not assume familiar forms at such extreme pressures and temperatures.
A 2.00-L glass soda bottle filled only with air is tightly capped at 25°C and 728.0 mmHg. If the bottle is placed in water at 65°C, what is the pressure in the bottle?
Answer:
The pressure in the bottle is 826 mmHg
Explanation:
In this case it is assumed that the volume of the soda bottle does not change, so it remains constant with a value of 2.00 L. Then it is possible to apply the Gay Lussac law.
This law indicates that when there is a constant volume, as the temperature increases, the gas pressure increases. And when the temperature decreases, gas pressure decreases. That is, the gas pressure is directly proportional to its temperature.
Gay-Lussac's law can be expressed mathematically as follows:
[tex]\frac{P}{T}=k[/tex]
Where P = pressure, T = temperature and K = Constant
Having a gas that is at a pressure P1 and a temperature T1, as the temperature varies to a new T2 value, then the pressure will change to P2. It is then fulfilled:
[tex]\frac{P1}{T1} =\frac{P2}{T2}[/tex]
Remember that the temperature must be in degrees Kelvin (° K) and that 0 ° C is 273.15 ° K
In this case you know:
P1= 728 mmHgT1= 25°C+273.15°K= 298.15°KP2= ?T2= 65°C+273.15°K= 338.15°KReplacing:
[tex]\frac{728 mmHg}{298.15K} =\frac{P2}{338.15K}[/tex]
Resolving you get:
[tex]\frac{728 mmHg}{298.15K} *338.15K=P2[/tex]
P2=825.67 mmHg≅826 mmHg
The pressure in the bottle is 826 mmHg
The pressure of the bottle is 825.7 mmHg
The parameters given in the question are
Pressure 1= 728 mmHg
Temperature 1= 25°C
= 25+273
T1= 298K
Temperature 2= 65°C
= 65 +273
= 338K
P1/T1= P2/T2
728/298= P2/338
Cross multiply
298 × P2= 728 × 338
298 × P2= 246,064
P2= 246,064/298
P2= 825.7
Hence the pressure in the bottle is 825.7 mmHg
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2 SO2(g) + O2(g) 2 SO3(g) Assume that Kc = 0.0680 for the gas phase reaction above. Calculate the corresponding value of Kp for this reaction at 84.5°C.
Answer: The corresponding value of [tex]K_p[/tex] for this reaction at 84.5°C is 0.00232
Explanation:
[tex]2SO_2(g)+O_2(g)\rightarrow 2SO_3(g)[/tex]
Relation of with is given by the formula:
[tex]K_p=K_c(RT)^{\Delta ng}[/tex]
where,
= equilibrium constant in terms of partial pressure = ?
[tex]K_c[/tex] = equilibrium constant in terms of concentration = 0.0680
R = Gas constant = [tex]0.0821\text{ L atm }mol^{-1}K^{-1}[/tex]
T = temperature =[tex]84.5^0C=(273+84.5)K=357.5K[/tex]
[tex]\Delta n_g[/tex] = change in number of moles of gas particles = [tex]n_{products}-n_{reactants}=2-3=-1[/tex]
Putting values in above equation, we get:
[tex]K_p=0.0680\times (0.0821\times 357.5)^{-1}\\\\K_p=0.00232[/tex]
Thus the corresponding value of [tex]K_p[/tex] for this reaction at 84.5°C is 0.00232
The combustion of glucose is represented by the following balanced equation: C6H12O6+6 O2→6 H2O+6 CO2. The reaction uses 1 gram of both C6H12O6 and O2. What is the percent yield if 0.45 g of H2O is produced? a 0.558% b 100% c 0.31% d 80%
Answer : The correct option is, (d) 80 %
Solution : Given,
Mass of [tex]C_6H_{12}O_6[/tex] = 1 g
Mass of [tex]O_2[/tex] = 1 g
Molar mass of [tex]C_6H_{12}O_6[/tex] = 180 g/mole
Molar mass of [tex]O_2[/tex] = 32 g/mole
Molar mass of [tex]H_2O[/tex] = 18 g/mole
First we have to calculate the moles of [tex]C_6H_{12}O_6[/tex] and [tex]O_2[/tex].
[tex]\text{ Moles of }C_6H_{12}O_6=\frac{\text{ Mass of }C_6H_{12}O_6}{\text{ Molar mass of }C_6H_{12}O_6}=\frac{1g}{180g/mole}=0.00555moles[/tex]
[tex]\text{ Moles of }O_2=\frac{\text{ Mass of }O_2}{\text{ Molar mass of }O_2}=\frac{1g}{32g/mole}=0.0312moles[/tex]
Now we have to calculate the limiting and excess reagent.
The balanced chemical reaction is,
[tex]C_6H_{12}O_6+6O_2\rightarrow 6H_2O+6CO_2[/tex]
From the balanced reaction we conclude that
As, 6 mole of [tex]O_2[/tex] react with 1 mole of [tex]C_6H_{12}O_6[/tex]
So, 0.0312 moles of [tex]O_2[/tex] react with [tex]\frac{0.0312}{6}=0.0052[/tex] moles of [tex]C_6H_{12}O_6[/tex]
From this we conclude that, [tex]C_6H_{12}O_6[/tex] is an excess reagent because the given moles are greater than the required moles and [tex]O_2[/tex] is a limiting reagent and it limits the formation of product.
Now we have to calculate the moles of [tex]H_2O[/tex]
From the reaction, we conclude that
As, 6 mole of [tex]O_2[/tex] react to give 6 mole of [tex]H_2O[/tex]
So, 0.0312 mole of [tex]O_2[/tex] react to give 0.0312 mole of [tex]H_2O[/tex]
Now we have to calculate the mass of [tex]H_2O[/tex]
[tex]\text{ Mass of }H_2O=\text{ Moles of }H_2O\times \text{ Molar mass of }H_2O[/tex]
[tex]\text{ Mass of }H_2O=(0.0312moles)\times (18g/mole)=0.562g[/tex]
Theoretical yield of [tex]H_2O[/tex] = 0.562 g
Experimental yield of [tex]H_2O[/tex] = 0.45 g
Now we have to calculate the percent yield of the reaction.
[tex]\% \text{ yield of reaction}=\frac{\text{ Experimental yield of }H_2O}{\text{ Theoretical yield of }H_2O}\times 100[/tex]
[tex]\% \text{ yield of reaction}=\frac{0.45g}{0.562g}\times 100=80\%[/tex]
Therefore, the percent yield of reaction is, 80 %
Answer:
The yield would D. 80%!
Explanation:
Since 1 gram of O2 only produces 0.56 g of H2O, whereas 1 g of C6H12O6 produces 0.60 g of H2O, the O2 is the limiting reagent.
In each case of a chemical reaction shown below, state the indicator of the chemical reaction. Identifying Indicators of Chemical Reactions Bread dough rising
Bread dough rises due to the formation of gas.
Explanation:
If we observe the outer part of the bread, which contains tiny hole like structure, due to the gas formation inside the bread dough.In the bread dough rising process, the industries are using the yeast, which makes the gas that separates the protein particles in the bread move apart and makes the dough of the bread rise.In this reaction, the yeast utilizing the carbohydrate to make a gas namely carbon-di-oxide gas which makes the dough to riseThe collapse point is an indicator of sufficient Bread dough rise.
Discussion;
When yeast is added to water and flour to create dough, it eats up the sugars in the flour and in turn produces carbon dioxide gas and ethanol in a process termed fermentation.
The elastic protein, gluten in the dough traps the carbon dioxide gas, preventing it from escaping.
In essence, the bread volume increases as the dough rises.
The collapse point is an indicator of sufficient dough rise.
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A solution of HCl gas dissolved in water (sold commercially as "muriatic acid," a solution used to clean masonry surfaces) has 20.22 g of HCl per 100.0 g of solution, and its density is 1.10 g/mL.
What is its molarity?
What is its mole fraction?
Answer:
[HCl] = 6.09 M
Xm HCl = 0.11
Explanation:
Let's analyse data:
20.22 g of solute / 100 g of solution
Solution's density = 1.10 g/mL
As we have the mass of solution and its density we determine solution's volume to stablish [M]
Density = Mass / volume → 1.10 g/mL = 100 g / Volume
100 g / 1.10g/mL = 90.9 mL
Let's convert the volume to L → 90.9 mL . 1L/ 1000mL = 0.0909L
We convert the mass of solute to moles → 20.22 g . 1mol/ 36.45g =
0.554 moles
[M] = Molarity (moles of solute /1L of solution) = 0.554 mol/0.0909L = 6.09M
Mole fraction (Xm) = Moles of solute / Total moles
Total moles = Moles of solute + Moles of solvent
Mass of solvent = Mass of solution - Mass of solute
Mass of solvent = 100 g - 20.22 g = 79.78g
We convert the mass to moles → 79.78 g / 18g/mol = 4.43 moles
Total moles = 4.43 moles + 0.554moles = 4.984 moles
Xm = 0.554 / 4.984 = 0.11
Final answer:
To find the molarity and mole fraction of the HCl solution, we calculate the molarity as 6.09 M and the mole fraction of HCl as 0.111 based on the given mass of HCl, solution density, and total solution mass.
Explanation:
To determine the molarity and mole fraction of a solution of HCl gas dissolved in water, we first need to calculate the mass of the solution and then convert the mass of HCl to moles. Given that the solution has 20.22 g of HCl per 100.0 g of solution, and its density is 1.10 g/mL, we can calculate the molarity and mole fraction as follows:
Calculating Molarity
Convert the mass of HCl to moles using the molar mass of HCl (36.46 g/mol):
20.22 g HCl * (1 mol HCl / 36.46 g) = 0.554 moles HCl. To find the volume of the solution, use the density and total mass:
100.0 g solution * (1 mL / 1.10 g) = 90.91 mL. Convert this to liters: 90.91 mL = 0.09091 L. Calculate molarity (M):
M = moles of solute / liters of solution = 0.554 moles / 0.09091 L = 6.09 M.
Calculating Mole Fraction
The mole fraction of HCl (XHCl) requires the number of moles of water:
(79.78 g water / 18.015 g/mol) = 4.43 moles of water. Calculate mole fraction of HCl:
XHCl = moles of HCl / (moles of HCl + moles of water) = 0.554 / (0.554 + 4.43) = 0.111.
How many hours will it take for the concentration of methyl isonitrile to drop to 14.0 %% of its initial value?
This is an incomplete question, here is a complete question.
The rearrangement of methyl isonitrile (CH₃NC) to acetonitrile (CH₃NC) is a first-order reaction and has a rate constant of 5.11 × 10⁻⁵ s⁻¹ at 472 K. If the initial concentration of CH₃NC is 3.00 × 10⁻² M :
How many hours will it take for the concentration of methyl isonitrile to drop to 14.0 % of its initial value?
Answer : The time taken will be, 10.7 hours
Explanation :
Expression for rate law for first order kinetics is given by:
[tex]t=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]
where,
k = rate constant = [tex]5.11\times 10^{-5}s^{-1}[/tex]
t = time passed by the sample = ?
a = let initial amount of the reactant = 100
a - x = amount left after decay process = 14 % of 100 = 14
Now put all the given values in above equation, we get
[tex]t=\frac{2.303}{5.11\times 10^{-5}}\log\frac{100}{14}[/tex]
[tex]t=38482.72s=\frac{38482.72}{3600}=10.7hr[/tex]
Therefore, the time taken will be, 10.7 hours
A student performs an experiment to determine the density of a sugar solution. She obtains the following results: 1.11 g/mL, 1.81 g/mL, 1.95 g/mL, 1.75 g/mL. If the actual value for the density of the sugar solution is 1.75 g/mL, which statement below best describes her results?
A) Her results are precise, but not accurate.
B) Her results are accurate, but not precise.
C) Her results are both precise and accurate
D) Her results are neither precise nor accurate.
E) It isn't possible to determine with the information given.
The answer is D, I don't know why they choose D?
Answer:
D. her results are neither precise, nor accurate
Explanation:
Reason being that: First, she obtained four different result for an experiment ( obviously it's supposed to be one value for the different procedure or atleast very close range) sugar solution and all four values were far apart.
Final answer:
The student's density measurements of a sugar solution were neither precise nor accurate because they varied widely from each other and, except one value, they also differed significantly from the known actual density value.
Explanation:
When a student performs an experiment to determine the density of a sugar solution and obtains results that vary greatly from the actual value, we must assess the precision and accuracy of the measurements. Accuracy refers to how close each measurement is to the true value, in this case, the actual density of 1.75 g/mL. Precision indicates how close the measurements are to each other, regardless of how close they are to the actual value.
In this scenario, the student's results show one measurement that is the same as the known actual value (1.75 g/mL), suggesting a single instance of accuracy. Therefore, the statement that best describes the student's results is that they are neither precise nor accurate, which corresponds to option D.
Hydrogen bonding among water molecules gives water all of the following important properties, except: strong cohesion among the individual water molecules. a transparent color. high heat capacity. the capacity to serve as a solvent to many other molecules. lower density as a solid than as a liquid.
Answer:
Answer here is A: Transparent colour."
Explanation:
Hydrogen bonds here in water provides a lot of benefits which includes cohesion, releasing heat when forming, Also because of the fact that water molecules are polar, they form hydrogen molecules and give water some characteristics which ranges from high boiling point, relative gravity, adhesion ad also cohesion. It is also known that oxygen atom attracts the electrons more strongly than the hydrogen.
A transparent colour falls in no place and do not really have any correlation in oxygen and hydrogen relationship.
Hydrogen bonding among water molecules gives water several important properties, including strong cohesion, high heat capacity, and the ability to serve as a solvent. However, it is not responsible for water's lower density as a solid compared to a liquid.
Explanation:Hydrogen bonding plays a crucial role in giving water several important properties. It allows for strong cohesion among water molecules, which contributes to its high surface tension and capillary action. This cohesion is also responsible for water's ability to serve as a solvent for many other molecules. Additionally, hydrogen bonding gives water a high heat capacity, meaning it can absorb and release a large amount of heat without changing temperature significantly. However, hydrogen bonding is not responsible for water's lower density as a solid compared to a liquid. This unique property is a result of the structure of water molecules and the open lattice arrangement they form in ice.
Learn more about Hydrogen bonding in water here:https://brainly.com/question/35107175
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Which of the soutions would have the HIGHEST hydrogen ion concentration?
Solution with a pH = 1
Solution with a pH = 12
Solution with a pH = 7
Solution with a pH = 9
Solution with a pH = 5
Answer:
Solution with a pH = 1
Explanation:
So the pH equation is pH = -log[H+]. To get the [H+] (hydrogen ion concentration), you rearrange to get [H+] = 10^-pH.
Solution with a pH = 1 , [H+] = .1 M
Solution with a pH = 12 , [H+] = 1*10^-12 M
Solution with a pH = 7 , [H+] = 1*10^-7 M
Solution with a pH = 9 , [H+] = 1*10^-9 M
Solution with a pH = 5, [H+] = 1*10^-5 M
Another way to get the answer: a high hydrogen ion concentration means that the solution should be more acidic. The most acidic pH of the 5 solutions is the one with a pH = 1.
Final answer:
The solution with a pH of 1 would have the highest hydrogen ion concentration, indicating it is the most acidic among the given options.
Explanation:
Out of the provided pH values, which solution would have the highest concentration of hydrogen ions? An indicator of how basic or acidic a solution is is the pH scale. High pH solutions are more basic, whereas low pH solutions are more acidic.
Because the pH scale is logarithmic, every pH value below 7 is ten times more acidic than the value immediately above it. For the options given, a pH of 1 indicates the highest acidity, implying the highest hydrogen ion concentration. This is due to the following relationship: pH = -log[H₃O⁺], where [H₃O⁺] represents the hydrogen ion concentration.
Therefore, a solution with a pH of 1 has a hydrogen ion concentration of 1.0 x 10⁻¹M, and is acidic.
22. Complete and balance the following acid-base equations: (a) A aqueous solution of HClO4 is added to an aqueous solution of LiOH. (b) Aqueous H2SO4 reacts with aqueous NaOH. (c) Ba(OH)2 solid reacts with HF gas.
Answer:
Answers are in the explanation
Explanation:
An acid-base equation in general is the reaction between an acid and a base that produce water and a salt. Thus:
a) HClO₄(aq) + LiOH(aq) → LiClO₄(aq) + H₂O(l)
Acid + Base → Salt + Water
b) H₂SO₄(aq) + 2NaOH(aq) → Na₂SO₄(aq) + 2H₂O(l)
Acid + Base → Salt + Water
c) 2HF(g) + Ba(OH)₂(s) → BaF₂ + 2H₂O
Acid + Base → Salt + Water
I hope it helps!
The combustion of ethane ( C 2 H 6 ) produces carbon dioxide and steam. 2 C 2 H 6 ( g ) + 7 O 2 ( g ) ⟶ 4 CO 2 ( g ) + 6 H 2 O ( g ) How many moles of CO 2 are produced when 5.30 mol of ethane is burned in an excess of oxygen?
Answer:
10.6 moles of CO₂ are produced in this combustion
Explanation:
The combustion reaction is:
2C₂H₆ (g) + 7O₂ (g) ⟶ 4CO₂ (g) + 6H₂O (g)
We assume the ethane as the limiting reactant because the excersise states that the O₂ is in excess.
We make a rule of three:
2 moles of ethane can produce 4 moles of CO₂
Therefore 5.30 moles of ethane will produce (5.3 . 4) /2 = 10.6 moles
hat is the relationship between the vapor pressure of a liquid and the measured pressure of the gas above the liquid at a given temperature in a closed system?
Answer:
In a closed system the vapor pressure and the measured pressure of a gas increases.
Explanation:
as the pressure of the liquid increases the measured pressures also increases with a given temperature.
A 0.10 mol sample of each of the four species in the reaction represented above is injected into a rigid, previously evacuated 1.0 L container. Which of the following species will have the highest concentration when the system reaches equilibrium?
a.H2S(g)
b.CH4(g)
c.CS2(g)
d.H2(g)
The question is incomplete. complete question is;
A 0.10 mol sample of each of the four species in the reaction represented above is injected into a rigid, previously evacuated 1.0 L container. Which of the following species will have the highest concentration when the system reaches equilibrium?
[tex]2H_2S+CH_4\rightleftharpoons CS_2(g)+4H_2(g)[/tex]
[tex]K_c=3.4\times 10^{-4}[/tex]
a.[tex]H_2S(g) [/tex]
b.[tex]CH_4(g) [/tex]
c.[tex]CS_2(g) [/tex]
d.[tex]H_2(g)[/tex]
Answer:
The correct answer is option a.
Explanation:
[tex]2H_2S+CH_4\rightleftharpoons CS_2(g)+4H_2(g)[/tex]
The equilibrium constant of the reaction= [tex]K_c=3.4\times 10^{-4}[/tex]
Concentration of the species initially:
[tex][H_2S]=\frac{0.10 mol}{1.0 L}=0.10 M[/tex]
[tex][CH_4]=\frac{0.10 mol}{1.0 L}=0.10 M[/tex]
[tex][CS_2]=\frac{0.10 mol}{1.0 L}=0.10 M[/tex]
[tex][H_2]=\frac{0.10 mol}{1.0 L}=0.10 M[/tex]
The equilibrium quotient of the reaction is :
[tex]Q_c=\frac{[CS_2][H_2]^4}{[H_2S]^2[CH_4]}[/tex]
[tex]=\frac{(0.10M)(0.10 M)^4}{(0.10 M)^2(0.10 M)}=0.01[/tex]
[tex]Q_c>K_c[/tex] (reaction will go backward)
[tex]2H_2S+CH_4\rightleftharpoons CS_2(g)+4H_2(g)[/tex]
Initially
0.10 M 0.10 M 0.10 M 0.10 M
At Equilibrium :
(0.10+2x) M (0.10+x) M (0.10-x) M (0.10-4x) M
[tex]K_c=\frac{[CS_2][H_2]^4}{[H_2S]^2[CH_4]}[/tex]
[tex]3.4\times 10^{-4}=\frac{(0.10-x)(0.10-4x)^4}{(0.10+2x)^2(0.10+x)}[/tex]
Solving formx:
x = 0.099 M
As we can see that from the reaction at equilibrium, the concentration of hydrogen sulfide will be highest:
[tex]=[H_2S]=(0.10+2x) M=(0.10+2\times 0.099) M=0.298 M[/tex]
The highest concentration at equilibrium has been of hydrogen sulfide. Thus, option A is correct.
The moles of reactants in the reaction has been 0.10 mol for each reactant. The balanced equation for the reaction has been:
[tex]\rm 2\;H_2S\;+\;CH_4\;\leftrightharpoons CS_2\;+\;4\;H_2[/tex]
The equilibrium quotient Q, for the reaction, has been given as:
[tex]Q=\dfrac{[CS_2]\;[H_2]^4}{[H_2S]^2\;[CH_4]}[/tex]
Computation for Equilibrium quotient :The equilibrium concentration of the reaction has been given in the image attached.
The initial value of equilibrium quotient, Qi has been:
[tex]Q_i=\dfrac{[0.1]\;\times\;[0.1]^4}{[0.1]^2\;[0.1]} \\Q_i=0.01[/tex]
The initial value of equilibrium quotient has been 0.01.
The equilibrium quotient, Ke value for equilibrium concentration:
[tex]3.4\;\times\;10 ^-^4=\dfrac{[0.10-x]\;[0.10-4x]^4}{[0.10+2x]^2\;[0.10 +x]} \\x=0.099\;M[/tex]
The concentration of compounds at equilibrium has been highest for hydrogen sulfide that is 0.298 M.
Thus, the highest concentration at equilibrium has been of hydrogen sulfide. Thus, option A is correct.
For more information about equilibrium concentration, refer to the link:
https://brainly.com/question/7949757
The______of water molecules and the hydrogen bonds between water molecules explain most of water's life-supporting properties.The_____of water molecules to each other helps transport water from the roots to the leaves in plants.
Polarity
Cohesion
Explanation:
One molecule of water joins with four other water molecule by hydrogen bonds. In a water molecule, one end has positive charge and the other end has negative charge. This difference in charge creates polarity in the molecule.
The cohesion of water molecules helps transport water from roots to the leaves in plants. Plants absorb water from the soil by osmosis. They absorb mineral ions by active transport, against the concentration gradient. Root hair cells are adapted for taking up water and mineral ions by having a large surface area to increase the rate of absorption.
Answer: Cohesion
Explanation:
Cohesion is a measure of how well molecules stick to each other. Water molecules is a typical example of Cohesion.
Hydrogen bonds are formed between each water molecule, enabling them stick to each other strongly. Due to this sticky nature of water molecules, they form droplets on surfaces (e.g dew drops) and a dome like-shape when filling a container just before it overflows.
Cohesion also produces Surface Tension; a phenomenon that makes it possible for light objects like needle to float when placed gently and insects to walk on water.
Also aided by capillary action (the movement of a liquid across the surface of a solid caused by adhesion between the two), Cohesion makes it possible for water to be taken as single huge molecule from Xylem in the roots of plant to its leaves.
Explain to Mark how composting can help reduce greenhouse gases
Explanation:
Compositing is the regulated breakdown of organic matter by microbes, aerobically. The major gas released from composting is carbon dioxide. This is different from landfills and manure piles where most of the breakdown of the organic matter happens, anaerobically because less oxygen penetrates the matter. Composting involves deliberate aeration of the decomposing matter. Anaerobic breakdown methane releases methane gas even more than carbon dioxide. Methane is four times more potent as a greenhouse gas than carbon dioxide. This is why composting is a good agricultural practice for mitigating climate change as compared to the use of landfills.
Answer:
Composting reduces the waste going to the landfill, which can lower methane emissions. It also promotes the growth of new plants and trees, which control the CO2 levels in the air. Mark could ask these two questions at the meeting:
What types of food waste will be composted?
How will the compost be used in the community?
Explanation:
This is the sample answer on edmentum
0.055 grams of PbSO4 is dissolved in 200.00 grams of H2O.
1. What is the mass of the total solution?
2. What is the concentration of the PbSO4 in ppm?
Answer:
Solution's mass = 200.055 g
[PbSO₄] = 275 ppm
Explanation:
Solute mass = 0.055 g of lead(II) sulfate
Solvent mass = 200 g of water
Solution mass = Solvent mass + Solution mass
0.055 g + 200 g = 200.055 g
ppm = μg of solute / g of solution
We convert the mass of solute from g to μg
0.055 g . 1×10⁶ μg/ 1g = 5.5×10⁴μg
5.5×10⁴μg / 200.055 g = 275 ppm
ppm can also be determined as mg of solute / kg of solution
It is important that the relation is 1×10⁻⁶
Let's verify: 0.055 g = 55 mg
200.055 g = 0.200055 kg
55 mg / 0.200055 kg = 275 ppm
Choose the chemical equation that is correctly balanced. 2Ca(s) + Cl2(g) → CaCl2(s) 4Mg(s) + O2(g) → 2MgO(s) Li(s) + Cl2(g) → 2LiCl(s) C(s) + O2(g) → CO2(g)
Answer:
Last option C(s) + O2(g) → CO2(g)
Explanation:
The reactions are:
2Ca(s) + Cl2(g) → CaCl2(s)
4Mg(s) + O2(g) → 2MgO(s)
Li(s) + Cl2(g) → 2LiCl(s)
C(s) + O2(g) → CO2(g)
Let's count the atoms (check out the stoichiometry):
1. We have 2 Ca in reactant side and 2Cl, in product side we have 1 Ca and 2 Cl. UNBALANCED
2. We have 4 Mg in reactant side and 2 O. In product side we have 2 Mg and 2 O. UNBALANCED
3. In reactant side we have 1 Li and 2 Cl. Then, in product side we have 2Li and 2Cl. UNBALANCED
C(s) + O2(g) → CO2(g)
1 C and 2 O ⇒ 1 C and 2 O Correctly balanced
The chemical equation [tex]\( \text{C(s)} + \text{O}_2\text{(g)} \rightarrow \text{CO}_2\text{(g)} \)[/tex] is correctly balanced. The correct option is (D).
To determine which chemical equation is correctly balanced, we need to ensure that the number of atoms for each element is the same on both sides of the equation. Let’s examine each option:
A) [tex]\( 2\text{Ca(s)} + \text{Cl}_2\text{(g)} \rightarrow \text{CaCl}_2\text{(s)} \)[/tex]
- Reactants: 2 Ca and 2 Cl
- Products: 1 Ca and 2 Cl
In this equation, the calcium (Ca) atoms are not balanced (2 Ca atoms on the left vs. 1 Ca atom on the right).
This equation is not balanced.
B) [tex]\( 4\text{Mg(s)} + \text{O}_2\text{(g)} \rightarrow 2\text{MgO(s)} \)[/tex]
- Reactants: 4 Mg and 2 O
- Products: 2 Mg and 2 O
In this equation, the magnesium (Mg) atoms are not balanced (4 Mg atoms on the left vs. 2 Mg atoms on the right).
This equation is not balanced.
C) [tex]\( \text{Li(s)} + \text{Cl}_2\text{(g)} \rightarrow 2\text{LiCl(s)} \)[/tex]
- Reactants: 1 Li and 2 Cl
- Products: 2 Li and 2 Cl
In this equation, the lithium (Li) atoms are not balanced (1 Li atom on the left vs. 2 Li atoms on the right).
This equation is not balanced.
D) [tex]\( \text{C(s)} + \text{O}_2\text{(g)} \rightarrow \text{CO}_2\text{(g)} \)[/tex]
- Reactants: 1 C and 2 O
- Products: 1 C and 2 O
In this equation, both carbon (C) and oxygen (O) atoms are balanced.
After analyzing the chemical equations, the only equation that is correctly balanced is:
[tex]\*\*D) \( \text{C(s)} + \text{O}_2\text{(g)} \rightarrow \text{CO}_2\text{(g)} \)\*\*[/tex]
To verify that the equation is balanced:
Carbon [tex](C)[/tex]:
- Reactants: 1 atom
- Products: 1 atom
Oxygen [tex](O)[/tex]:
- Reactants: 2 atoms
- Products: 2 atoms
Since the number of atoms for each element is the same on both sides of the equation, it confirms that option D is the correct and balanced chemical equation.
The complete question is:
Choose the chemical equation that is correctly balanced.
A) [tex]2Ca(s) + Cl_2(g) \rightarrow CaCl_2(s)[/tex]
B) [tex]4Mg(s) + O_2(g) \rightarrow 2MgO(s)[/tex]
C) [tex]Li(s) + Cl_2(g) \rightarrow 2LiCl(s)[/tex]
D) [tex]C(s) + O_2(g) \rightarrow CO_2(g)[/tex]
Early life arose in an oxygen-free environment, but if any of these microbes had somehow come in contact with oxygen, the most likely effect would have been ________.
Answer:
the effect of oxygen on these types of microbes is it will kill them.
Explanation:
When oxygen present in the environment come in contact with anaerobe bacteria it kill them because oxygen in air act as excited oxygen singlet molecule which will react with the water present in the cell of bacteria and convert it into hydrogen peroxides and bacteria do not have any defense system from hydrogen peroxide and ultimately it kill the bacteria.
How can you tell if a chemical compound is ionic or covalent by just looking at the formula?
Answer: Ionic compounds ( Metal + Non-metal), Covalent Compounds (Non-metal + Non metal ).
Explanation: Going by the definition, an ionic compound is formed when a chemical reaction occurs between a metal and a non-metal while a covalent compound is formed when a chemical reaction occurs between two non-metals.
Having a good knowledge of the periodic table, one can easily identify the metals and non-metals in each compound and thus tell if it is Ionic or Covalent.
By examining the formula of a chemical compound, one can tell if it is ionic or covalent. Ionic compounds consist of metals combined with nonmetals or polyatomic ions, whereas covalent compounds are formed from nonmetals only.
Explanation:To determine if a chemical compound is ionic or covalent just by looking at the formula, we consider the types of elements involved in the compound. Typically, ionic compounds are formed when a metal and a nonmetal react, resulting in the transfer of electrons and the formation of ions. For example, NaCl (sodium chloride) is an ionic compound because it consists of the metal sodium (Na) and the nonmetal chlorine (Cl).
In contrast, covalent compounds are formed when nonmetals bond together, leading to the sharing of electrons. An example of a covalent compound is H2O (water), which comprises the nonmetals hydrogen (H) and oxygen (O). Also, if the compound contains a recognizable polyatomic ion like NO3− (nitrate), which typically forms ionic bonds with metals, it can be identified as ionic. For instance, Ba(NO3)2 includes the nitrate ion and the metal barium (Ba), indicating an ionic compound.