The equilibrium constant, Kc, for the reaction H2 (g) + I2 (g) ⇄ 2HI (g) at 425°C is 54.8. A reaction vessel contains 0.0890 M HI, 0.215 M H2, and 0.498 M I2. Which statement is correct about this reaction mixture?
a. The reaction quotient is greater than 1.
b. The reaction is not at equilibrium and will proceed to make more products to reach equilibrium.
c. The reaction mixture is at equilibrium.
d. The reaction is not at equilibrium and will proceed to make more reactants to reach equilibrium.

b. The reaction is not at equilibrium and will proceed to make more products to reach equilibrium.

Explanation:

Step 1: Data given

Kc at 425 °C = 54.8

[HI] = 0.498 M

[H2] = 0.215 M

[I2] = 0.498 M

Step 2: The balanced equation

H2 (g) + I2 (g) ⇄ 2HI (g)

Step 3: Calculate Q

Kc = 54.8

Q = [HI]² / [H2][I2]

Q = (0.0890)² / (0.215)(0.498) = 0.074

When Q<<Kc, there are more reactants than products. As a result, some of the reactants will become products, causing the reaction to shift to the right

Option B is correct: b. The reaction is not at equilibrium and will proceed to make more products to reach equilibrium.

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.