Questions 1-4 refer to gas contained in a cylinder which is equipped with a freely sliding piston.
1 The kinetic energy of gas molecules is directly proportional to ......
a ....... the temperature of the gas.
b ....... the pressure of the gas.
c ...... the work done on the gas by the piston.
d ...... the velocity of the gas molecules.
2 The gas trapped in the cylinder is a mixture of hydrogen and carbon dioxide. Which of the following statements is incorrect.
a Some molecules will be moving faster than others at any given time.
b The average speed of the hydrogen molecules is very much greater than the average speed of the carbon dioxide molecules.
c Molecular speeds fit the Maxwell Boltzman distribution.
d All molecules have the same speed.
3 When the piston is suddenly pushed down the gas is compressed and the temperature rises. This is an example of......
a ...... an adiabatic process
b ..... an isobaric process
c .... an isothermal process
d ....... an esoteric process
4 When the piston is pushed down ..........
a ...... pressure, volume and temperature all change.
b ...... only the pressure and the volume change.
c ...... only the volume and the temperature change
d ..... the product PV remains constant.
5 A swimming pool contains one thousand cubic meters of water. The specific heat of water is 4200 joules per kilogram degree C. The energy needed to heat the pool by 10 degrees Celsius is.....
a 4200000000 Joules
b 42000000000 Joules
c 420000000000 Joules
d 4200000000000 Joules
6 A kettle is boiling. The energy input is a steady 1500 joules per second. The temperature of the boiling water will rise above 100°C if........
a ... the air pressure rises.
b .... energy input is doubled.
c .... salt is added to the water.
a All are correct.
b Only a and b are correct .
c Only b and c are correct.
b Only a and c are correct.
7 A liter of alcohol (ethanol) is boiled in an electric jug. The ethanol rises in temperature more quickly than a liter of water in the same electric jug. It boils at 80°C. These findings can be accounted for by saying that.......
a ... ethanol has a lower specific heat than water.
b ...ethanol has a higher specific heat than water.
c ...ethanol has a lower specific heat and a lower boiling
point than water.
d ...ethanol and water do not mix.
*8 An air conditioner transfers air from outside to inside. It is found to be dripping water. Which statement is not necessarily correct?
a The air inside the building has less water vapor per liter than air outside.
b The relative humidity inside is less than that outside.
c The dew point inside the room is lower than that outside.
d The air inside is cooler than the air outside.
9 When a bike pump is used to inflate a tire the pump is found to get hot. This effect is due to.....
a The work done on the gas by the piston.
b The isothermal nature of the compressions.
c The change in the volume of the compressed gas.
d Avagadro's principle.
10 Thermodynamics is the study of.......
a Engines.
b Heat transfer.
c The motion of gas molecules.
d Flame throwers.