# Calorimetry Practice Problems -- key.docx - Calorimetry...

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Calorimetry Practice Problems -- key 1. How much energy is needed to change the temperature of 50.0 g of water by 15.0 o C? q = mc T q = (50.0)(4.184)(15.0) 3.14 x 10 3 J 2. How many grams of water can be heated from 20.0 o C to 75 o C using 12500.0 Joules? q= mc T 12500.0 = m (4.184)(55) 54.3 g 3. What is the final temperature after 840 Joules is absorbed by 10.0g of water at 25.0 o C? q = mc T 840 = 10.0(4.184) T T= 20.1 o C, therefore T f = 45.1 o C 4. The heat capacity of aluminum is 0.900 J/g o C. How much energy is needed to raise the temperature of a 8.50 x 10 2 g block of aluminum from 22.8 o C to 94.6 o C? q = (8.50 x 10 2 )(0.900)(71.8) 54900 J 5. A piece of metal weighing 59.047 g was heated to 100.0 °C and then put it into 100.0 mL of water initially at 23.7 °C. The metal and water were allowed to reach thermal equilibrium, determined to be 27.8 °C. Assuming no heat lost to the environment, calculate the specific heat
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