1) Express the equilibrium constant for the following
reaction.
P4O10(s) ⇌ P4(s) + 5
O2(g)
a) K = [O2]-5
b) K = [O2]5
c) K =
d) K =
2) For the reaction of carbon with carbon dioxide to make carbon
monoxide, the reaction is as follows. Write the equilibrium
constant expression for the Kc.
C(s) + CO2(g) ⇌ 2CO(g)
a) Kc =
b) Kc =
c) Kc =
d) Kc =
3) Which of the following statements is FALSE?
a) When K is very large, the forward reaction is favored and
essentially goes to completion.
b) None of the answers are correct.
c) If K is very large it implies that the reaction is very fast
at producing products.
d) When K is very small, the reverse reaction is favored and the
forward reaction does not proceed to a great extent.
4)The equilibrium constant for the production of carbon dioxide
from carbon monoxide and oxygen is 
the reaction mixture at equilibrium is likely to consist of
a) mostly starting materials.
b) twice as much starting material as product.
c) mostly products.
d) twice as much product as starting material.
5) Which chemicals never appear in the K expression? Choose all
that apply.
a) gas
b) aqueous
Answer
Equilibrium constant i.e. Kis ratio of the
product of the molar concentration of products to the product of
the molar concentration of reactants raised to the power of
stoichiometric coefficients with respect to each reagent at
equilibrium stage of the reaction.
NOTE :- While writing the expression of K, the
concentration of pure liquids and
solids are considered as
constant.
So,
1. Ans :- Option (b) i.e.
K = [O2]5 is the correct
answer.
2. Ans :- Option (c) i.e.
Kc =
is the correct answer.
3. Ans :- Option (b) i.e.
None of the answers is the correct answer.
4. Ans :- Option (c) i.e.
Mostly products is the correct answer.
Explanation :-
For given reaction, CO (g) + 1/2 O2 (g)
<----------> CO2 (g)
The equilibrium constant Kc can be written as,
![CO2 ] c=[C0102]1/2-2x10 11 -=](https://answerdata.org/wp-content/uploads/2021/12/653f8272f5ff.png "653f8272f5ff")
rearranging, ![[CO_2]=2times 10^{11}times [CO][O_2]^{1/2}](https://answerdata.org/wp-content/uploads/2021/12/3557b977733f.png "3557b977733f")
it means, the concentration of products is 
times the concentration of reactants at equilibrium.
Therefore, reaction mixture at equilibrium is mostly consists of
mostly products.
Hence, Option (c) is the correct answer.