1. Calculate the standard enthalpy change, ΔHo, for the formation of 1 mol of strontium carbonate (the material that gives the red color in fireworks) from its elements.
Sr(s) + C(graphite) + 3/2O2(g) → SrCO3(s)
The information available is
(1) Sr(s) + 1/2O2(g) → SrO(s) ΔHo = -592 kJ
(2) SrO(s) + CO2(g) → SrCO3(s) ΔHo = -234 kJ
(3) C(graphite) + O2(g) → CO2(g) ΔHo = -394 kJ
2. The combination of coke and steam produces a mixture called coal gas, which can be used as a fuel or as a starting material for other reactions. If we assume coke can be represented by graphite, the equation for the production of coal gas is
2C(s) + 2H2O(g) →CH4(g) + CO2(g)
Determine the standard enthalpy change for this reaction from the following standard enthalpies of reaction:
(1) C(s) + H2O(g) → CO(g) + H2(g) ΔHo = 131.3 kJ
(2) CO(g) + H2O(g) → CO2(g) + H2(g) ΔHo = -41.2 kJ
(3) CH4(g) + H2O(g) → 3H2(g) + CO(g) ΔHo = 206.1 kJ
3. The enthalpy change due to a temperature change is a change in
A. kinetic energy.
B. potential energy.
4. An enthalpy change at constant temperature and pressure is designated by the symbol
A. q
B. H
C. ΔH
D. c
5. The molar enthalpy change for a process is designated by the symbol
A. q
B. H
C. ΔH
D. c
6. Another word for melting is _______________.
7. Another word for boiling is _______________.
8. Calculate the enthalpy change when a 10.0 g of water is heated from 10.0°C to 25.0°C. Show working.
9. Calculate the enthalpy change when 10.0 g of water at 100°C is converted to 10.0 g of Vapor at 100°C. Show work.
10. Calculate the total change in enthalpy when 100 g of ice at -5.00°C is converted to water at 85.00°C. Show work (hint show two q and one ΔH.)
Review the following Youtube video:
https://www.youtube.com/watch?v=_NLAgSnqNOE