Calorimetry Problems Worksheet 2
1. A reaction occurs in a calorimeter containing 200.0 g of water with an initial
temperature of 22.0oC. The temperature of the water changes to 17.5oC.
a) Was the reaction endothermic or exothermic? Explain.
b) Calculate H in kilojoules.
2. Exactly 4.50 kJ of heat energy was released by a reaction in a calorimeter. The
temperature of the water changed by 34.0oC. Calculate the mass of water in the
calorimeter.
3. When 450. J of heat energy was added to a 25.0 g certain substance, its
temperature increased from 23.0oC to 25.0oC. Determine the specific heat of this
substance.
4. A calorimeter contains 250.0 g of water at an initial temperature of 25.0 oC. A
reaction occurring in the calorimeter absorbs 850. J of heat energy. Determine the
final temperature of the water.
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5. A reaction occurring in a calorimeter containing 100.0 g of water produces a
temperature change from 21.0oC to 34.0oC.
a) Was the reaction endothermic or exothermic? Explain.
b) Determine the quantity of heat energy involved.
6. Exactly 2.77 g of a hydrocarbon was burned in a calorimeter containing 100.0 g
of water. The temperature of the water increased from 23.0oC to 74.5oC.
a) Calculate the amount of heat energy involved in the reaction.
b) Express your answer above in kJ/g of hydrocarbon.
c) If the hydrocarbon has a molar mass of 192 g/mol, express your answer in
kJ/mol of hydrocarbon.
7. A 3.50 g sample of nickel metal at a temperature of 88.0oC is placed into a 50.0 g
sample of water at 25.0oC. What will be the final temperature of both the metal
and water after “thermal equilibrium” is reached? The specific heat capacity of
nickel is 0.444 J/goC.
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