Semester exam questions! oof!

1. given the following equation: n2 (g) + 3 h2 (g) ↔ 2nh3 (g) δh = -92 kj/mol
a. is this reaction exothermic or endothermic?
b. what direction will the equilibrium shift if nitrogen gas is removed?
c. what direction will the equilibrium shift if the temperature is lowered?
d. what direction will the equilibrium shift if ammonia (nh3) is added?
e. what principle you answer b-d?

e. I will answer the last one first - the equation describes a reversible reaction and the equilibrium is determined by the Le Châtelier's principle.

a. It is exothermic.

b. It will shift towards the reactants side (N2+H2).

c. It will shift towards the product side (NH3).

d.  It will shift towards the reactants side (N2+H2).

points

explanation:

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.