Thermochemistry: Practice Questions
1. If heat is released, the reaction is thermic. (H is: choose one: (+ or -)
If heat is absorbed, the reaction is thermic. (H is: choose one: (+ or -)
2. Draw energy diagrams for Cd(s) + 1/2 O2(g) ( CdO(s) + 260.4 kJ. Indicate the axes, reactants and products, (H, identify whether the reaction is exothermic and endothermic.
3. Given the following equation: Na2O(s) + 2HI(g) ( 2 NaI(s) + H2O(l) + 501.6 kJ
a) If 9.00 g of NaI are formed by the process, how much heat (q) will be involved? (15.0 kJ)
b) State whether the reaction is endothermic or exothermic.
4. When concentrated nitric acid HNO3 is added to water, heat is liberated. This “heat of solution” is 30.09 kJ/mol of HNO3 diluted. How many grams of nitric acid must be diluted to release 3611.52 kJ of heat? (7.564 kg)
5. Given a) C(diamond) + O2(g) ( CO2(g) (H = -395.01 kJ/mol
b) C(graphite) + O2(g) ( CO2(g) (H = -393.13 kJ/mol
Calculate the (H for the manufacturing of diamond from graphite. (1.88 kJ)
6. Calculate the (H for the reaction: C(s) + H2O(g) ( CO(g) + H2(g)
using the following information:
C(s) + O2(g) ( CO2(g) (H = -392.92 kJ/mol
CO(g) + 1/2 O2(g) ( CO2(g) (H = -282.57 kJ/mol
H2(g) + 1/2 O2(g) ( H2O(g) (H = -241.60 kJ/mol
7. Given the following equation:
2 NaHSO4(s) ( Na2SO4(s) + H2O(g) + SO3(g) (H = + 230.74 kJ
If 3.60 g of NaHSO4 react, how much heat is evolved? (3.46 kJ)
8. Given the following equation C(s) + O2(g) ( CO2(g) (H = -392.92 kJ
a) How many grams of carbon must be burned to produce 2553.98 kJ of energy?
b) How many grams of oxygen will be consumed in the production of this energy? (208.0 g)
9. Calculate the (H for the reaction H2(g) +...