Chapter 6 Worksheet 1

1. Which would decrease the internal energy of your body?

a. lying in the sunb. sitting in an air conditioned classroom where its COLDc. taking a hot bathd. eating foode. None of these

2. What is the heat capacity of a metal slug if a temperature rise from 25 C to 54 C requires 135 J? Units are Degrees Celsius.

a. 0.21 J/ Cb. 4.7 J/ Cc. 0.60 J/ Cd. 2.5 J/ Ce. -4.6 J/ C

3. A 295-g aluminum engine part at an initial temperature of 3.00°C absorbs 85.0 kJ of heat. What is the final temperature of the part (°C)?(c of Al = 0.900 J/g·K)?

a. –2.68°Cb. 3.32°Cc. 323°Cd. 317°C

4. Data: ΔHf values: CH4(g), -74.8 kJ; CO2(g), -393.5 kJ; H2O(l), -285.8 kJ. Using the ΔHf data above, calculate ΔHrxn for the reaction below.

Reaction: CH4(g) + 2O2(g) => CO2(g) + 2H2O(l)

a. -604.2 kJb. 890.3 kJc. -997.7 kJd. -890.3 kJe. none of the above

5. A 134 g aluminum engine part at an initial temperature of 16.9°C absorbs 2,389 J of heat. What is the final temperature of the part (°C)? (c of Al = 0.900 J/g·K)?

6. Data:2C8H18(l) + 25O2(g) => 16CO2(g) + 18H2O(l) ΔH = -11,200. kJ

Standard enthalpies of formation, ΔHf:CO2(g), -393.5 kJ/mol; H2O(l), -285.8 kJ/mol

Use the above data to calculate the standard enthalpy of formation of octane, C8H18(l).

a. -120. kJ/molb. -240. kJ/molc. -5144 kJ/mold. -6296 kJ/mole. -11,440. kJ/mol

7. Data:2Fe(s) + O2(g) => 2FeO(s) ΔH = -544.0 kJ4Fe(s) + 3O2(g) => 2Fe2O3(s) ΔH = -1648.4 kJFe3O4(s) => 3Fe(s) + 2O2(g) ΔH = +1118.4 kJ

Given the data above, determine the heat of reaction, ΔH, for the reaction below:Reaction: Fe2O3(s) + FeO(s) => Fe3O4(s)

a. -1074.0 kJb. -22.2 kJc. +22.2 kJd. +249.8 kJe. +1074.0 kJ

8. A 2.15 g sample of benzene (C6H6) is burned in a bomb calorimeter, and the temperature rises from 22.46 C to 34.34 C. Calculate the heat capacity of the bomb calorimeter. Note the following thermochemical equation:

9. When 50. mL (50. g) of 1.00 M HCl at 22.00 °C is added to 50. mL (50. g) of 1.00 M NaOH at 22.00 °C in a coffee cup calorimeter, the temperature increases to 28.87 °C. What is the heat (q) of the reaction between HCl and NaOH? (The specific heat of the solution produced is 4.18 J/g°C.)