Question

1. The following reaction was performed in a sealed vessel at 732 ∘C : H2(g)+I2(g)⇌2HI(g)

Initially, only H2 and I2 were present at concentrations of [H2]=3.25M and [I2]=3.00M. The equilibrium concentration of I2 is 0.0600 M . What is the equilibrium constant, Kc, for the reaction at this temperature?

Express your answer numerically.

2. The decomposition of HI(g) is represented by the equation: 2HI(g)⇌H2(g)+I2(g)

The following experiment was devised to determine the equilibrium constant of the reaction.

HI(g) is introduced into five identical 400-cm3 glass bulbs, and the five bulbs are maintained at 623 K.The amount of I2 produced over time is measured by opening each bulb and titrating the contents with 0.0150 M Na2S2O3(aq). The reaction of I2 with the titrant is I2+2Na2S2O3→Na2S4O6+2NaI

What is the value of Kc for the decomposition of HI at 623 K?

3. The equilibrium constant for the reaction SO2(g)+NO2(g)⇌SO3(g)+NO(g) is 3.1.

Find the amount of NO2 that must be added to 2.3 mol of SO2 in order to form 1.2 mol of SO3 at equilibrium.

4. At a certain temperature the initial concentration of NO was 0.400 M and that of Br2 was 0.265 M . At equilibrium the concentration of NOBr was found to be 0.250 M.

What is the value of Kc at this temperature?

5. The reaction of CH4 is carried out at a different temperature with an initial concentration of [CH4] = 8.7×10⁻² M . At equilibrium, the concentration of H2 is 1.2×10⁻² M .
2CH4(g)⇌C2H2(g)+3H2(g)

Find the equilibrium constant at this temperature.

6. The following reaction was carried out in a 2.50 L reaction vessel at 1100 K: C(s)+H2O(g)⇌CO(g)+H2(g)

If during the course of the reaction, the vessel is found to contain 7.75 mol of C, 15.0 mol of H2O, 3.10 mol of CO, and 6.00 mol of H2, what is the reaction quotient Q?

Enter the reaction quotient numerically.

7. The equilibrium constant for the reaction SO2(g)+NO2(g)⇌SO3(g)+NO(g) is 3.1.

Find the amount of NO2 that must be added to 2.3 mol of SO2 in order to form 1.2 mol of SO3 at equilibrium.

Answer 1

Answer to question (1)

Reaction given:

H_2(g)+I_2(g)⇌2HI_(g)

Initial Concentration of H_2(g) =3.25 M

Initial concentration of I_2(g) = 3.00 M

Let us recall the reaction

H_2(g)      +      I_2(g)      ⇌        2HI_(g)

3.25               3                    -

3.25-x           3-x                    2x

It is given that equilibrium concentration of I₂ = 0.0600 M

Hence 3-x =0.06

Therefore x=3-0.06 = 2.94 M

Final concentration of H2 = 3.25 -x =3.25-2.94 = 0.31 M

Final concentration of HI = 2x = 2*2.94 = 5.88 M

Kc expression is as follows,

Substituting all the values of concentration to obtain the value of Kc

Kc= 1858.838

The value of equilibrium constant for the above reaction is 1858.838