Exam 3 Name: ____________________
November 8, 2011 Chemistry 1110-001 I.D.#: ____________________
1. The standard state for a gas is defined a 25°C and 1 atm of pressure.
A. True B. False
2. Calculate the density of NO2 at 35°C and 746 torr? [MW(NO2)=46.0g/mol, R = 0.082 L-atm/
mol-K]
A. 11.123 g/L B. 1.235 g/L C. 1.786 g/L D. 2.136 g/L E. 4.527 g/L
3. The amount of heat required to raise the temperature of 56 grams of substance by 35°C (K) is
called its
A. heat capacity B. molar heat capacity C. specific heat
4. All of the following are postulates of the kinetic-molecular theory of gases except
A. The collisions between molecules are elastic.
B. The gas moleucles are in constant motion.
C. At a constant temperature, each molecule has the same kinetic energy.
D. The volume of the moleucles are negligible compared with the volume of the conatainer.
E. The gas molecules are in rapid motion.
5. A 75.2-g sample of metal at 70.0°C is added to 165.0 g of H2O at 22.0°C. The final temperature of
the water was measured to be 26.3°C. Assuming that the calorimeter is a perfect insulator, what is
the specific heat of the metal? [specific heat of H2O is 4.184 J/g•°C]
A. 0.848 J/g•°C B. 0.244 J/g•°C C. 0.581 J/g•°C
D. 0.725 J/g•°C E. 0.905 J/g•°C
6. Which of the following is inconsistent with the kinetic theory of an ideal gas?
A. The forces of repulsion between gas molecules are very weak or negligible.
B. Most of the volume occupied by a gas is empty space.
C. When gas molecules collide, they both gain kinetic energy.
D. The average kinetic energy of a gas is proportional to the absolute temperature.
E. Gas molecules move in a straight line between collisions.
7. Which of the following is not a state function ?
A. Pressure B. distance C. Temperature
D. Enthalpy E. Volume
8. A reaction for which !H= -56kJ/mol is said to be
A. endergonic B. exothermic C. exogonic D. endothermic
9. The specific heat of aluminum is 0.902 J/g-K. How much heat in Joules is required to raise the
temperature of 25 g of aluminum from 35 oC to 87 oC?
A. 3529 J B. 1731 J C. 1137 J D. 2935 J E. 1173 J
10. A gas occupies a volume of 360 mL at 35°C. If the volume is increased to 480 mL at constant
pressure what is the final temperature of the gas in degrees Celcius?
A. 381 °C B. 138 °C C. 318°C D. 831 °C E. 183 °C
