Chem Unit 8
11. A gas occupies a volume of 0.7 L at 10.1 kPa. What volume will the gas occupy at 101 kPa?
.07 L
38. When a container is filled with 3 moles of H2, 2 moles of O2, and 1 mole of N2, the pressure in the container is 8787 kPa. What is the partial pressure of O2?
256 kPa
12. A sample of gas occupies 40.0 mL at -123¶C. What volume does the sample occupy at 27¶C?
80 ml
21. If a balloon is rubbed vigorously, what happens to the pressure of the air inside the balloon if the volume remains constant?
it will increase
40. Which gas is the best choice to serve as the inflating gas of a balloon that must remain inflated for a long period of time?
Argon
33. If oxygen is removed from the air in the process of rusting, what happens to the partial pressure of oxygen in the air?
It decreases
34. If oxygen is removed from the air by the process of rusting, what happens to the total pressure of the air?
It decreases
10. The volume of a gas is reduced from 4 L to 0.5 L while the temperature is held constant. How does the gas pressure change?
It increases
35. What happens to the partial pressure of oxygen in the air if the air temperature is increased?
It increases
36. If the volume of a container of air is reduced by one-half, what happens to the partial pressure of oxygen within the container?
It is doubled
25. At low temperatures and pressures, how does the volume of a real gas compare with the volume that would be predicted for an ideal gas under the same conditions?
It is less
24. At very high pressures, how does the volume of a real gas compare with the volume that would be predicted for an ideal gas under the same conditions?
It is much greater
9. The volume of a gas is doubled while the temperature is held constant. How does the gas pressure change?
It is reduced by one half
15. What happens to the average Kinetic energy of a gas as the temperature of the gas in a balloon decreases?
It will decrease
7. What happens to the pressure of a gas inside a container if the temperature of the gas is lowered?
It will decrease
14. What will happen to the pressure as the temperature of a fixed volume of a gas increases?
It will increase
8. If a balloon is squeezed, what happens to the air pressure within the balloon?
It will increase
32. Under what conditions of temperature and pressure is the behavior of real gases most like that of ideal gases?
Low temperature and high pressure
31. At a certain temperature and pressure, 0.20 mol of CO2 has a volume of 3.1 L. What can be said of a 3.1-L sample of hydrogen at the same temperature and pressure?
Contains the same number of molecules
37. A breathing mixture used by deep-sea divers contains helium, oxygen, and carbon dioxide. What is the partial pressure of oxygen at 101 kPa if PHe = 84 kPa and element subscript element = 0.1 kPa?
Dalton's Law: Ptotal = P1 + P2 + P3 . . . ; 101 kPa = 84kPa + 0.1kPa + P3; P3= 101kPa - (84kPa + 0.1kPa); P3 = 16.9 kPa
39. What is the tendency of molecules to move toward areas of lower concentration called?
Diffusion
4. Why does increasing the volume of a given amount of gas at constant temperature causes the pressure to decrease?
Molecules are striking a large area with the same force
26. Can an ideal gas be liquefied?
No
29. What does the ideal gas law allow a scientist to calculate that the other laws do not?
Number of moles
28. What is constant for 1 mole of any ideal gas?
PV/T
30. What is the normal form of the ideal gas law?
PV= nRT
23. What 3 things are related in the combined gas law?
Pressure, volume and temperature
16. What does Boyle's law state?
That for a given mass of gas at constant temperature, the volume of the gas varies inversely with pressure.
13. Why does an aerosol can become cooler when gas is released?
The gas propellant moved from a region of high pressure to a region of low pressure
2. Why does air leave a tire when the tire valve is opened?
The pressure outside the tire is lower than the pressure inside the tire
3. If 4 moles of gas are added to a container that already holds 1 mole of gas, how will the pressure change within the container?
The pressure will be five times higher
5. If the volume of a container holding a gas is reduced, what will happen to the pressure within the container?
The pressure will increase
20. When the pressure and number of particles are kept constant for a sample of gas, what other two things also remain constant for the sample?
The ratio of the volume and temperature in kelvin
27. When the volume and number of particles are held constant for a sample of gas, what other two things are also constant for the sample?
The ratio of the volume and temperature in kelvin
6. What happens to the temperature of a gas when it is compressed?
The temperature increases
19. What does Charles' law state?
The volume of a fixed mass of gas is directly proportional to its Kelvin temperature, if the pressure is kept constant
1. Why does the pressure inside a container of gas increase if more gas is added to the container?
There is an increase in the number of collisions between particles and the walls of the container
22. What are the two things that are directly proportional for a gas at constant volume?
Volume and absolute temperature
17. When the temperature and number of particles are kept constant for a sample of gas, what 2 things also remain constant for the sample?
Volume and mass
18. If a balloon is rubbed vigorously, what happens to the volume of the air in the balloon if the pressure is constant?
Volume increases
