Question

1. Which of the following processes have a Q value at equilibrium which increases as the temperature increases
a) mixing of H2SO4 and H2O
b) dissolving of O2(g) in H2O
c) 2Cl(g) -> Cl2
d) H2O(l) -> H2O(s)
e) dissolving of sugar in H2O

2. The instant you open a bottle of Diet Coke, which of the following describes the thermochemistry of bubble formation?
a) delta G > 0, Q > 0 b) delta G < 0, Q>0 c) delta G > 0. Q < 0 d) delta G < 0, Q < 0 e) need to know if K is >0 to answer

Thank you!

Answer 1

1.

The equilibria for exothermic processes / reactions are shifted to the backward or reactant side by increase in temperature thereby increasing the concentration of reactants, therefore Kc becomes lesser . Since Q values are related to Kc as under,

Q > Kc ....... The reaction will proceed in the direction of reactants [reverse reaction]

Q < Kc ........ The reaction will proceed in the direction of the products [ forward reaction ]   

So. considering the exothermic or endothermic nature of given processes / reaction,

The following processes would result into increase in Q values with increase in temperature-

a ) mixing of sulphuric acid in water

b) dissolving of O2(g) in water

c) 2Cl (g) -----> Cl2

Note:

actually, this question appears to be a question with more than one correct answers, hence a),b) & c) are identified a correct answers, because they include reactions / processes which are exothermic in nature.

2. answer ,....................d) delta G < 0, Q < 0

Since a negative value of delta G causes an spontaneous process , and a Q value lesser than zero ( ie. the Q value at equilibrium ) favours forward processes / reaction.