The Gas Laws Unit Test Review and Test 96%
Consider the reaction. 3Mg(s) + 2H3PO4(aq) -> Mg3(PO4)2(s) + 3H2(g) Which statement is true at STP? (The atomic mass of Mg is 24.31 u.)
(3 x 24.31) g of Mg produce (3 x 22.4) L of H2 gas.
The volume of a gas is 450 mL when its pressure is 1.00 atm. If the temperature of the gas does not change, what is the pressure when its volume is changed to 2.00 L?
0.225 atm
A scientist is examining a mixture of nitrogen, hydrogen, and ammonia. The individual pressures that are exerted by nitrogen and hydrogen are 0.26 atm and 0.28 atm, respectively. If the total pressure is 0.90 atm, what is the partial pressure of ammonia?
0.36 atm
A tire at 21°C has a pressure of 0.82 atm. Its temperature decreases to -3.5°C. If there is no volume change in the tire, what is the pressure after the temperature change?
0.75 atm
Consider the reaction. C(s) + O2(g) -> CO2(g) How many grams of carbon should be burned in an excess of oxygen at STP to obtain 2.21 L of carbon dioxide?
1.18 g
How many moles of oxygen (O2) are present in 33.6 L of the gas at 1 atm and 0°C?
1.5
If 6.00 g of carbon is burned completely, what volume of carbon dioxide gas is released at STP?
11.2 L
What volume would 3.01•1023 molecules of oxygen gas occupy at STP?
11.2 L
Consider this reaction. mc030-1.jpg What volume (in milliliters) of oxygen gas is required to react with 4.03 g of Mg at STP?
1860 mL
What is the volume of 0.200 mol of an ideal gas at 200. kPa and 400. K?
3.33 L
A balloon that had a volume of 3.50 L at 25.0°C is placed in a hot room at 40.0°C. If the pressure remains constant at 1.00 atm, what is the new volume of the balloon in the hot room?
3.68 L
Consider the equation. mc016-1.jpg Which represents the correct mass-volume relationship at STP?
32.00 g of O2 react with an excess of H2 to produce (2 ´ 22.4) L of H2O.
According to the equation 2Na + 2H2O mc012-1.jpg 2NaOH+H2, what mass of Na is required to yield 22.4 L of H2 at STP? (The atomic mass of Na is 22.99 u.)
46.0 g
Which law states that the volume of a gas is proportional to the moles of the gas when pressure and temperature are kept constant?
Avogadro's law
Which law is based on the graph that is shown below?
Boyle's law
Which law is described by saying that when the pressure of a gas in a sealed container is cut in half, the gas will double in volume at a steady temperature?
Boyle's law
Which law states that the pressure and absolute temperature of a fixed quantity of gas are directly proportional under constant volume conditions?
Charles's law
The absolute temperature of a gas is increased four times while maintaining a constant volume. What happens to the pressure of the gas?
It increases by a factor of four.
The volume of a gas decreases to half of its original volume, but the gas maintains the same number of moles and temperature. According to the ideal gas law, what will most likely happen to the pressure?
It will double.
If a gas is moved from a large container to a small container but its temperature and number of moles remain the same, what would happen to the pressure of the gas?
It would increase.
The pressure of 1 mol of gas is decreased to 0.5 atm at 273 K. What happens to the molar volume of the gas under these conditions?
The molar volume is doubled
Which statement can best be concluded from the ideal gas law?
The product of pressure and volume of an ideal gas is proportional to the absolute temperature.
Which describes the volume of 1 mol of gas at standard temperature and pressure?
The volume is the same for any gas.
The gases listed are at standard temperature and pressure: · 1 mol of CO2 gas · 1 mol of N2 gas · 2 mol of O2 gas Which statement is correct?
The volumes of 1 mol of CO2 and 1 mol of N2 gases are the same.
Shana solves stoichiometry problems using the equation for the synthesis of water. 2H2(g) + O2(G) -> 2H2O(g) Which interpretation of the balanced equation would cause Shana to make a mistake?
Two grams of hydrogen react with one gram of oxygen to form two grams of water.
Which proportionality shows the result of combining Avogadro's law with Boyle's law?
V = n/P
A student uses 0.0821 L• atm/mol • K as the value of the gas constant. What is most likely true about the variables in the ideal gas law?
V has the units of liters, and T has the units of kelvin.
Consider the proportionality below. mc009-1.jpg What does this best represent?
ideal gas law
Which law relates temperature, pressure, volume, and the number of moles of a gas under perfect conditions?
ideal gas law
Which quantity is held constant when working with Boyle's, Charles's, and Gay-Lussac's laws?
moles
The table below shows a comparison of the different gas laws. Some cells have been left blank. Which are assumed to be constant while using the combined gas law?
number of moles
The ideal gas constant, R has several different values that could be used. Which quantity causes these differences?
pressure
Which best defines partial pressure in a mixture of gases?
pressure that is exerted by one gas as if it occupied a container by itself
The gas in the piston is at constant temperature. A student increases the pressure on the piston from 2 atm to 3 atm. The observation will be summarized in a row of the incomplete table below. Which row of the table and which observation would the student fill?
row 1, volume decreases when pressure increases
The gas in the piston is being heated, and the piston has moved upward. The observation will be summarized in a row of the incomplete table below. mc023-1.jpg What are the variables for this piston?
temperature and volume
If the pressure, volume, and temperature of a gas are known, which can most likely be found by using the ideal gas law?
the molar amount of the gas
Which correctly defines molar volume of an ideal gas?
the volume that is occupied by 1 mol of an ideal gas at STP, which is 22.4 L
