Chemistry

Chemical Equilibrium and Stoichiometry

135 Questions

Chemical equilibrium and stoichiometry questions cover equilibrium constants, percent yield, and the Haber process. These concepts test your ability to calculate reaction outcomes and purity. Practice these to excel in physical chemistry sections of competitive tests.

Equilibrium constant calculationsStoichiometric yieldHaber processPercent purityHomogenous equilibrium

Chemical Equilibrium and Stoichiometry Questions

Multiple choice chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

Consider the equilibrium $NH _{4}Cl (s)\rightleftharpoons NH _{3}(g) + HCl(g)$. An inert gas is added to the system at constant volume and temperature. The correct statement(s) is/ are:

  1. the partial pressures of $NH _{3}$ and $HCl$ in the system will increase
  2. the partial pressures of $NH _{3}$ and $HCl$ in the system will remain the same
  3. the partial pressures of $NH _{3}$ and $HCl$ in the system will decrease

  4. the entropy of the system will increase
Reveal answer Fill a bubble to check yourself
B,D Correct answer
Explanation

$NH _4$ $+$ $Cl(s)$ $\rightleftharpoons$ $NH _3 (g)$ $+$ $HCl$.

Noble gas are  inert hence adding inert gas doesn't effect the partial pressure.
This is because noble gas gets added to both reactant and product.
$X (g)$ $+$ $NH _4Cl (S)$ $ \rightleftharpoons $ $NH _3(g)$ $+$ $HCl(g)$ $+$ $X(g)$
Where X=Noble gas
Hence the partical presence of $NH _3$ and $HCl$ will remain same.
The amount of gas in the system will increase after adding inert gas.
Since gases has high entropy than liquid and solid, the entropy  of the system will increase.  

Multiple choice

The equilibrium constant (K) for a chemical reaction is defined as:

  1. The ratio of products to reactants at equilibrium

  2. The ratio of reactants to products at equilibrium

  3. The difference between products and reactants at equilibrium

  4. The sum of products and reactants at equilibrium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The equilibrium constant (K) is defined as the ratio of products to reactants at equilibrium.

Multiple choice

What is the equation of exchange?

  1. MV = PQ

  2. M/P = VQ

  3. P = MV/Q

  4. Q = MV/P
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The equation of exchange is a fundamental equation in monetary economics that relates the quantity of money in circulation (M), the velocity of money (V), the price level (P), and the quantity of goods and services produced (Q). It states that the total value of all transactions in an economy (MV) is equal to the total value of all goods and services produced (PQ).

Multiple choice

The equilibrium constant for a chemical reaction is:

  1. The ratio of the concentrations of the reactants to the concentrations of the products.

  2. The ratio of the activities of the reactants to the activities of the products.

  3. The ratio of the partial pressures of the reactants to the partial pressures of the products.

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The equilibrium constant for a chemical reaction is the ratio of the concentrations, activities, or partial pressures of the reactants to the concentrations, activities, or partial pressures of the products.

Multiple choice

The equilibrium constant for a reaction is:

  1. The ratio of the concentrations of the reactants to the concentrations of the products.

  2. The ratio of the activities of the reactants to the activities of the products.

  3. The ratio of the partial pressures of the reactants to the partial pressures of the products.

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The equilibrium constant for a reaction is the ratio of the concentrations, activities, or partial pressures of the reactants to the concentrations, activities, or partial pressures of the products.

Multiple choice

What is the relationship between the equilibrium constant (K) and the concentrations of reactants and products at equilibrium?

  1. K = [products]/[reactants]

  2. K = [reactants]/[products]

  3. K = [products]^2/[reactants]^2

  4. K = [reactants]^2/[products]^2
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The equilibrium constant (K) is equal to the ratio of the concentrations of products and reactants at equilibrium.

Multiple choice

What is the equation for the equilibrium constant of a chemical reaction?

  1. K = [products]/[reactants]

  2. K = [reactants]/[products]

  3. K = ln([products]/[reactants])

  4. K = ln([reactants]/[products])
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The equilibrium constant of a chemical reaction is equal to the ratio of the concentrations of the products to the concentrations of the reactants, at equilibrium.

Multiple choice

What is the equation for the Raoult's law?

  1. P_total = P_A + P_B

  2. P_total = P_A - P_B

  3. P_total = P_A * P_B

  4. P_total = P_A / P_B
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Raoult's law states that the total vapor pressure of a solution is equal to the sum of the vapor pressures of the pure components of the solution.

Multiple choice

What is the equation for the Henry's law?

  1. P = k_H * X

  2. P = k_H / X

  3. P = X / k_H

  4. P = 1 / (k_H * X)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Henry's law states that the partial pressure of a gas in a solution is proportional to the mole fraction of the gas in the solution.

Multiple choice

The equilibrium equation of a structure is:

  1. [K]{U} = {F}

  2. [K]{U} = 0

  3. [M]{U} = {F}

  4. [M]{U} = 0
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The equilibrium equation of a structure is [K]{U} = {F}, where [K] is the stiffness matrix, {U} is the displacement vector, and {F} is the force vector.

Multiple choice

The equilibrium constant for a chemical reaction is defined as:

  1. The ratio of the concentrations of the reactants to the concentrations of the products.

  2. The ratio of the partial pressures of the reactants to the partial pressures of the products.

  3. The ratio of the activities of the reactants to the activities of the products.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The equilibrium constant for a chemical reaction is defined as the ratio of the concentrations of the reactants to the concentrations of the products, the ratio of the partial pressures of the reactants to the partial pressures of the products, and the ratio of the activities of the reactants to the activities of the products.

Multiple choice

What is the atom economy of the following reaction? $$C_6H_6 + 3Cl_2 → C_6H_6Cl_6$$

  1. 18.2%

  2. 27.3%

  3. 36.4%

  4. 45.5%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The atom economy of the reaction is calculated as follows: $$Atom economy = rac{Molecular weight of C_6H_6Cl_6}{Molecular weight of C_6H_6 + 3Cl_2} = rac{290.8}{78.1 + 213.0} = 0.182$$ Therefore, the atom economy of the reaction is 18.2%.

Multiple choice

What is the atom economy of the following reaction? $$2C_2H_5OH + 3O_2 → 4CO_2 + 6H_2O$$

  1. 90.9%

  2. 81.8%

  3. 72.7%

  4. 63.6%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The atom economy of the reaction is calculated as follows: $$Atom economy = rac{Molecular weight of 4CO_2 + 6H_2O}{Molecular weight of 2C_2H_5OH + 3O_2} = rac{176.0 + 108.0}{92.1 + 96.0} = 0.909$$ Therefore, the atom economy of the reaction is 90.9%.

Multiple choice

What is the atom economy of the following reaction? $$CH_4 + 2O_2 → CO_2 + 2H_2O$$

  1. 33.3%

  2. 44.4%

  3. 55.5%

  4. 66.6%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The atom economy of the reaction is calculated as follows: $$Atom economy = rac{Molecular weight of CO_2 + 2H_2O}{Molecular weight of CH_4 + 2O_2} = rac{44.0 + 36.0}{16.0 + 64.0} = 0.333$$ Therefore, the atom economy of the reaction is 33.3%.

Multiple choice

What is the atom economy of the following reaction? $$2C_6H_5CH_3 + 3O_2 → 12CO_2 + 6H_2O$$

  1. 77.8%

  2. 88.9%

  3. 99.0%

  4. 110.1%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The atom economy of the reaction is calculated as follows: $$Atom economy = rac{Molecular weight of 12CO_2 + 6H_2O}{Molecular weight of 2C_6H_5CH_3 + 3O_2} = rac{528.0 + 108.0}{182.2 + 96.0} = 0.778$$ Therefore, the atom economy of the reaction is 77.8%.