2H2O(g) ? 2H2(g) + O2(g) (?H = +483.6 kJ)
Write the thermochemical equation for this reaction and tell whether it is exothermic or endothermic.
2) Increasing temperature increases the rate of a reaction. What are the other 4 factors affecting reaction rate? Why does a higher temperature increase reaction rate?
3) When a 10.25 g sample of solid NH4NO3 dissolves in 87.5 g of water in a calorimeter, the temperature drops from 21.1°C to 14.7°C. Determine the quantity of heat for this solution process. (the specific heat of water is 4.184 J/g·C°)
4) Briefly explain the relationship between the temperature, transfer of heat, and heat capacity of a liquid.
5) Nitric oxide, NO, decomposes into nitrogen and oxygen gas according to this reaction:
2NO(g) ? N2(g) + O2(g) ?H = –90.3 kJ
Calculate the heat evolved per gram of nitrogen monoxide.
6) When a 4.25 g sample of solid ammonium nitrate dissolves in 60.0 g of water in a coffee-cup calorimeter, the temperature drops from 22.0°C to 16.9°C. Calculate ?H (in kJ/mol of NH4NO3) for the solution process
NH4NO3(s) ? NH4+(aq) + NO3-(aq)
Assume that the specific heat of the solution is the same as that of pure water.
7) Write the equilibrium constant equation (K) for the following reaction:
CaCO3(s) ? CaO(s) + CO2(g)
8) Write the equilibrium constant equation (K) for the following reaction:
2NH3(g) <--> N2(g) + 3H2(g)
9) If the value of K is small, which of the following is true? (circle one)
10) Write the acid ionization constant (Ka) for the following reaction:
H2CO3(aq) + H2O(l) <--> H3O+(aq) + HCO3-(aq)
11) Consider the following reaction:
2NH3(g) + 92kJ/mol <--> N2(g) + 3H2(g)
(for each of the following, write either “increase” or “decrease”)
to the [H2] if:
a. you increase [N2]?
b. you increase [NH3]?
c. you decrease the temperature?
d. you decrease [N2]?
(for each of the following write either “forward” or “reverse”)
does the equilibrium shift (forward or reverse) if:
a. you increase [N2]?
b. you decrease [H2]?
c. you increase the temperature?
d. you increase the pressure?
12) Based on the Potential Energy Diagram provided below, answer the following questions: