RoseMarie Gallagher and Paul Ingram Solutions for Chapter: Energy Changes, and Reversible Reactions, Exercise 8: Checkup on Chapter 9

Ammonia is made from nitrogen and hydrogen. The energy change in the reaction is $-92 \mathrm{kJ} /\mathrm{mole}$. The reaction is reversible, and reaches equilibrium. Is the forward reaction endothermic, or exothermic? Give your evidence.

Ammonia is made from nitrogen and hydrogen. The energy change in the reaction is $-92 \mathrm{kJ} /\mathrm{mole}$. The reaction is reversible, and reaches equilibrium. Explain why the yield of ammonia rises if you increase the pressure.

Ammonia is made from nitrogen and hydrogen. The energy change in the reaction is $-92 \mathrm{kJ} /\mathrm{mole}$. The reaction is reversible, and reaches equilibrium. Explain why the yield of ammonia falls if you increase the temperature.

Ammonia is made from nitrogen and hydrogen. The energy change in the reaction is $-92 \mathrm{kJ} /\mathrm{mole}$. The reaction is reversible, and reaches equilibrium. What effect does increasing the pressure have on the rate at which ammonia is made?

Ammonia is made from nitrogen and hydrogen. The energy change in the reaction is $-92 \mathrm{kJ} /\mathrm{mole}$. The reaction is reversible, and reaches equilibrium. What effect does increasing the temperature have on the rate at which ammonia is made?

Ammonia is made from nitrogen and hydrogen. The energy change in the reaction is $-92 \mathrm{kJ} /\mathrm{mole}$. The reaction is reversible, and reaches equilibrium. Why is the reaction carried out at $450°\mathrm{C}$ rather than at a lower temperature?

The dichromate ion ${\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}$ and chromate ion ${\mathrm{CrO}}_4^{2-}$ exist in equilibrium, like this:

$\underset{\mathrm{orange}}{{\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\rightleftharpoons \underset{\mathrm{yellow}}{2{\mathrm{CrO}}_4^{2-}}\left(\mathrm{aq}\right)+2{\mathrm{H}}^{+}\left(\mathrm{aq}\right)$

What would you see if you added dilute acid to a solution containing chromate ions?

The dichromate ion ${\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}$ and chromate ion ${\mathrm{CrO}}_4^{2-}$ exist in equilibrium, like this:

$\underset{\mathrm{orange}}{{\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\rightleftharpoons \underset{\mathrm{yellow}}{2{\mathrm{CrO}}_4^{2-}}\left(\mathrm{aq}\right)+2{\mathrm{H}}^{+}\left(\mathrm{aq}\right)$

How would you reverse the change?