The kinetic particle theory states that
p = k(1/v) --> pV = k
where k is a constant
1. Which property of gas affects the rate at which it spreads throughout a laboratory?
a. boiling point
b. molecular mass
d. solubility in water
2. Four identical gas jars are filled with different gases. The lids are taken off the gas jars and they are left open to the air for a few hours. Which gas jar will then have the most air in it?
3. The conical flask contains compound X which is present in the solid, liquid and gaseous states. Which statement is correct?
a. energy is released when X changes from liquid to solid
b. a gaseous X molecule has a lower mass than a liquid X molecule
c. liquid X is at a higher temperature than solid X
d. liquid X molecules vibrate about fixed positions
4. The table shows the boiling points of some of the gases present in air.
When air is cooled to -200oC, some of these gases liquefy. Which gases liquefy?
a. argon, helium, neon
b. argon, nitrogen, oxygen
c. helium, neon, nitrogen
d. helium and neon
5. By which process does the smell of cooking spread to all the rooms in a house?
6. What can be deduced about two gases that have the same molecular mass?
a. they have the same solubility in water at room temperature
b. they have the same boiling point
c. they have the same number of atoms in one molecule
d. they have the same rate of diffusion at room temperature and pressure
7. The cover-plates were removed from the gas jars as shown in the diagram. After several days, the colour of the gas was the same in both jars.
Which statement explains this change?
a. oxygen and bromine gases have equal densities
b. oxygen and bromine molecules are in random motion
c. oxygen and bromine molecules diffuse at the same rate
d. equal volumes of oxygen and bromine contain equal numbers of molecules
8. Which of the following would diffuse most rapidly?
9. The kinetic theory of matter states that all matter is made up of
a. a small number of tiny particles
b. a large number of tiny particles
c. a small number of large particles
d. a large number of large particles
10. Which one of the following conditions increases the rate of movement of particles in matter?
a. increase in density
b. decrease in mass
c. increase in volume
d. increase in temperature
11. Ice is less dense than water because the ice molecules
a. are smaller than the water molecules
b. are different from the water molecules
c. are more loosely packed than the water molecules
d. move faster than the water molecules
12. Boyle's Law is valid for a gas at constant
13. The volume of a certain gas at constant temperature is reduced by 1/2. The pressure of the gas will be
a. 1/4 of its original value
b. 1/2 of its original value
c. twice its original value
c. four times its original value
14. A balloon filled with hydrogen expands as it ascends because
a. its surrounding pressure decreases
b. its surrounding pressure increases
c. its temperature increases
d. its temperature decreases
15. A given mass of air occupies 12 m3 at normal atmospheric pressure. If the pressure is increased to 4 times the original value without changing the temperature, what volume will the air occupy?
a. 3 m3
b. 6 m3
c. 24 m3
d. 48 m3
e. 192 m3
16. In one minute, a diver breathes 1 litre of air at an atmospheric pressure of 100 kPa. To breathe in the same mass of air in one minute, how much air would he need to breathe when the total pressure on him under water is 300 kPa?
a. 1/3 litre
b. 1/2 litre
c. 1 litre
d. 2 litres
e. 3 litres
17. Some gas trapped in a cylinder is compressed at constant temperature by a piston. Which of the following will not change?
c. molecular spacing
18. What can be deduced about two gases with the same relative molecular mass?
a. They have equal solubility in water at room temperature.
b. They have the same number of atoms in one molecule.
c. They have the same rate of diffusion at room temperature and pressure.
d. They have the same melting point.
19. One way to remove toxic nitrogen monoxide (NO) from motor vehicle exhaust is to inject a stream of ammonia gas into the exhaust vapour.
6NO (g) + 4NH3 (g) ---> 5N2 (g) + 6H2O (g)
A car emits 3 dm3 of nitrogen monoxide for each kilometre it moves. If it is driven 40,000 km a year, what is the volume of ammonia gas needed per annum to clean up te exhaust gas?
a. 40,000 dm3
b. 60,000 dm3
c. 80,000 dm3
d. 120,000 dm3
20. The particles in the gas can be described as
a. expanding in fixed directions
b. moving randomly in all directions
c. vibrating about a fixed position
d. rising upwards
21. In an air-conditioned bus, water is slowly collected on the glass window panes. This process is best described by
22. Which of the following atoms has a nucleus which does not contain any neutrons?
23. Which of the following groups consists of mixtures only?
a. chlorine, water, salt
b. chlorine, water, sand
c. salt, water, salt
d. salt, air, brass
24. During the formation of ionic bond, the atoms taking part
a. gain protons
b. lose and gain protons
c. lose and gain electrons
d. gain electrons
25. Which of the following compounds are formed as a result of sharing electrons?
a. calcium chloride
b. oxygen gas
c. iron(III) oxide
26. Which of the following solids does not contain any covalent bonds?
27. Which of the following would diffuse most rapidly?
27. c (it has the smallest relative molecular mass)
a. complete the table by filling in the boxes.
A student heated some solid ammonium chloride, NH4Cl in a test-tube. Ammonia and one other gas were formed. He tested the gases coming out of the tube with litmus paper.
b. name the process which caused the gases to move along the tube
c. which gas turned red litmus paper blue?
d. which gas turned the litmus paper red?
1d. hydrogen chloride
2. In both liquids and gases, the molecules present are moving.
a. compare the movements and the spacing between the molecules in a gas with those in a liquid
b. how do these movements change as the temperature is increased?
c. how does your answer in (a) explain how the rates of chemical reactions change as the temperature of the reaction mixture is increased?
2a. The molecules in a gas move very vigorously at random. The molecules are far apart. In a liquid, the molecules are closer and move less vigorously. They only slide between the layers. There are still forces of attraction between the liquid molecules.
2b. As temperature is increased, the movement of molecules speeds up and they move further apart. For gases, this causes an expansion while in liquids expansion also occurs but when enough energy is obtained by the particles, they will break away from the forces holding them in liquid state and will change to gas. These particles will collide more often.
2c. The rates of chemical reactions corresponds with the rate of collision of the particles in the reactants. Hence the chemical reaction is faster.
3a. The diagram represents the arrangement of the particles in a solid.
i. describe the movement of the particles in the solid
ii. how does this movement alter as the temperature of the solid is increaseD?
iii. how does this movement alter as the solid melts?
b. Samples of the gases carbon dioxide, Mr = 44, and hydrogen, Mr = 2, are at the same temperature. Compare the speeds of the molecules in these two gases.
c. Equal masses of steam and of water contain the same number of molecules. Explain why the volume of the steam is much greater than that of the water.
3ai. Particles in the solid are fixed in orderly arrangement and they vibrate about fixed positions.
3aii. They vibrate more vigorously as energy is absorbed.
3aiii. They move about as the forces holding the particles together break.
3b. The average molecular speeds of hydrogen molecules are higher.
3c. In steam, the molecules are more energetic and are further away from one another. The volume of steam is thus higher.
4. A tyre contains 1500 cm3 of air at pressure p. The volume of air in the pump is 500 cm3 at the same pressure p. What will be the pressure in the tyre after one stroke of the pump, assuming the volume of the tyre and the temperature of the air do not change?
p1V1 = p2V2
p1 x (1500 + 500) = p2 x 1500
p2 = 4/3 p1
5. An air balloon at the bottom of a pond has a volume of 5cm3. The depth of the pond is 40 m. Assuming that the temperature remains constant, calculate the volume of the balloon when it reaches the surface, where the atmospheric pressure is equal to 10 m water.
at the bottom of the pond, pressure acting on the balloon,
p1 = 40 + 10 = 50 m water
volume of balloon, V1 = 5 cm3
At the surface of the pond, p2 = 10 m water
volume of balloon, V2 = V
According to equation pV = constant
p1V1 = p2V2
50 x 5 = 10 x V
V = 25 cm3
6. A fixed mass of air occupies 9.0 litres at a temperature of 300 K and a pressure of 1.2 atmospheres. The volume is reduced to 5.0 litres by increasing the pressure to 2.3 atmospheres.
a. assuming that the air behaves as an ideal gas, calculate the temperature of the air after the reduction in volume
b. give one reason why the actual temperature may be different from that you have calculated.
6a. V1 = 9 cm3
V2 = 5cm3
P1 = 1.2 atmosphere
P2 = 2.3 atmosphere
T1 = 300 K
to find T2,
P1V1 / T1 = P2V2 / T2
(1.2 X 9) / 300 = (2.3 X 5) / T2
T2 = 319.4 K
6b. Air does not behave like an ideal gas.
7. A bubble of air at the bottom of a lake has a volume of 3.0 cm3 and the pressure on it is equivalent to 4.5 atmospheres. Assuming that the temperature remains constant, calculate the volume of the bubble when it reaches the surface, where the pressure is 1.0 atmosphere.
Suggest, in terms of the forces acting on it, why the bubble rises towards the surface.
let volume of bubble be V2
p1V1 = p2V2
4.5 x 3 = 1 x V2
V2 = 13.5 cm3
The weight of the air bubble is much smaller compared to the upthrust of water on it. This initial resultant upward force causes the bubble to move upwards.
8ai. Describe the motion of the molecules of a gas
8aii. What type of motion does a sound wave give to the molecules of air?
8aiii. What effect does a sound wave have on the pressure of air as the wave moves through it?
8b. A bicycle pump of volume 72 cm3 is filled with air at a pressure of 0.100 MPa. The volume is reduced to 30 cm3. No air leaks from the pump and the temperature stays constant. Calculate the pressure of the compressed air.
8ai. random and continuous
8aiii. An alternate series of high and low pressure regions is produced.
8b. Using Boyle's Law,
p1V1 = p2V2
0.100 x 72 = p2 x 30
p2 = 0.240 MPa
9. The graph below shows the heating curve of a pure substance.
a. What is the melting point of the substance?
b. What happens to the temperature while the substance changes state? Explain your answer.
c. Explain why the substance cannot be water.
9b. It remains at a constant temperature until the change in state is completed. At 80ºC, the solid particles absorb heat energy to break the forces of attraction between them. The amount of energy supplied at this point is equal to the amount of energy needed to break the forces of attraction holding the particles in fixed position. At 215ºC, the heat energy supplied is only sufficient to cause the liquid particles to move further apart into a state of randomness. No further rise in temperature will occur until all the forces of attraction in a liquid has been broken.
9c.Water has a melting point of 0ºC and a boiling point of 100ºC. The graph shows a substance that melts at 80ºC and boils at 215ºC.
10. In both liquids and gases, the molecules present are moving.
i. Compare the movements and the spacing between the molecules in a gas with those in a liquid.
ii. How do these movements change as the temperature is increased?
iii. How does your answer to (ii) explain how the rates of chemical reactions change as the temperature of the reaction mixture is increased?
10i. In a gas, the molecules are very far apart and they are moving randomly around the space available. In a liquid the molecules are still quite closely packed, with the molecules sliding over each other.
10ii. As temperature of a gas is increased, the particles will move more vigorously and further apart. In a liquid, the particles will move faster, eventually breaking the forces of attraction that hold them together at boiling point and moving into a state of randomness when a gas is formed.
10iii. The rate of a chemical reaction corresponds to the rate of effective collision between reactant particles. With an increase in temperature, the reactant particles will gain more kinetic energy and move faster, collide more often, leading to an increase in reaction rate.