Sk015 Chapter 6 Chemical Equilibrium

When the system A + B C + D is at equilibrium,

• A. the sum of the concentrations of A and B must equal the sum of the concentrations of C and D.

• B. the forward reaction has stopped.

• C. the reverse reaction has stopped.

• D. neither the forward nor the reverse reaction has stopped.

2SO₃(g) ≒ 2SO₂(g) + O₂(g)

The conventional equilibrium constant expression (K_c) for the system as described by the above equation is:

• A. [SO₂]²/[SO₃]

• B. [SO₂]²[O₂]/[SO₃]²

• C. [SO₃]²/[SO₃]²[O₂]

• D. [SO₂][O₂]

Consider the following reversible reaction. In a 3.00 liter container, the following amounts are found in equilibrium at 400 oC: 0.0420 mole N2, 0.516 mole H2 and 0.0357 mole NH3. Evaluate Kc.
N2(g) + 3H2(g)  -->2NH3(g)

• A, 0.202

• B. 1.99

• C. 16.0

• D. 4.94

At 445^oC, K_c for the following reaction is 0.020.

2HI(g) ≓ H₂(g) + I₂(g)

A mixture of H₂, I₂, and HI in a vessel at 445^oC has the following concentrations: [HI] = 2.0 M, [H₂] = 0.50 M and [I₂] = 0.10 M. Which one of the following statements concerning the reaction quotient, Q_c, is TRUE for the above system?

• A. Q_c = K_c; the system is at equilibrium.

• B. Q_c is less than K_c; more H₂ and I₂ will be produced.

• C. Q_c is less than K_c; more HI will be produced.

• D. Q_c is greater than K_c; more H₂ and I₂ will be produced.

Consider the gas-phase equilibrium system represented by the equation:

2H₂O(g) ≒ 2H₂(g) + O₂(g)

Given that the forward reaction (the conversion of "left-hand" species to "right-hand" species) is endothermic, which of the following changes will decrease the equilibrium amount of H₂O?

• A. adding more oxygen

• B. adding a solid phase calalyst

• C. decreasing the volume of the container (the total pressure increases)

• D. increasing the temperature at constant pressure

The conventional equilibrium constant expression (K_c) for the system below is:

2ICl(s) ≒ I₂(s) + Cl₂(g)

• A. [I₂][Cl₂]/[ICl]²

• B. [I₂][Cl₂]/2[ICl]

• C. [Cl₂]

• D. [Cl₂]/[ICl]²

Consider the equilibrium system:

2ICl(s) ≒ I₂(s) + Cl₂(g)

Which of the following changes will increase the total amount of of Cl₂ that can be produced?

• A. removing some of the I₂(s)

• B. adding more ICl(s)

• C. removing the Cl₂ as it is formed

• D. decreasing the volume of the container

K_c = 0.040 for the system below at 450^oC:

PCl₅(g) ≓ PCl₃(g) + Cl₂(g)

Evaluate K_p for the reaction at 450^oC.

• A. 0.40

• B. 0.64

• C. 2.4

• D. 5.2

For a specific reaction, which of the following statements can be made about K, the equilibrium constant?

• A. It changes with changes in the temperature.

• B. It always remains the same at different reaction conditions.

• C. It increases if the concentration of one of the products is increased.

• D. It increases if the concentration of one of the reactants is increased.

What are the two factors to look for when determining if the reaction is at equilibrium?

• Forward reaction rate is faster than the reverse and concentrations are equal
• Forward and reverse reaction rates are equal and concentration is constant
• Forward and revers reaction rates are equal and concentration is equal
• Forward reaction rate is faster than the reverse and concentration is equal

Tags

NGSS.HS-PS1-5

NGSS.HS-PS1-6