1. A system absorbs 196kJ of heat and the surroundings do 117kJ of work on the system. What is the change in internal energy of the system?
2. A gas is compressed from an initial volume of 5.55L to a final volum of 1.22L by an external pressure of 1.00atm. During the compression the gas release 124J of heat. What is the change in internal energy of the gas?
3. Mothballs are composed primarily of the hydrocarbon naphthalen (C10H8).When 1.025g of naphthalene burns in a bomb calorimeter, the tempurature rises from 24.250C to 32.330C. Find delta(Erxn) for the combustion naphthalen. The heat capacity of the calorimeter, determined in a separate experiment, is 5.11kJ/0C.
5. When 0.514g of biphenyl (C12H10) undergoes combustion in a bomb calorimeter, the temperature rises from 25.80C to 29.40C. Find ∆Erxn for the combustion of biphenyl in kJ/mol biphenyl. The heat capacity of the bomb calorimeter, determined in a seperate experiment, is 5.86kJ/0C
6. One tablespoon of peanut butter has a mass of 16g. It is combusted in a calorimeter whose heat capacity is 120kJ/0C. The temperature of the calorimeter rise from 22.20C to 25.40C. Find the food caloric content of peanut butter.
7. For the reaction: CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l); ΔHo = -891 kJ.
Calculate ΔH for a reaction in which 4.50 g of CH4 is burned at constant pressure.
» Tin mới nhất:
» Các tin khác: