Chemistry Exam 4
In a gas mixture of He, Ne, and Ar with a total pressure of 8.40 atm, the mole fraction of Ar is __________ if the partial pressures of He and Ne are 1.50 and 2.00 atm, respectively.
0.583
A mixture of He and Ne at a total pressure of 0.95 atm is found to contain 0.32 mol of He and 0.56 mol of Ne. The partial pressure of Ne is __________ atm.
0.60
SO2 (5.00 g) and CO2 (5.00 g) were placed in a 750.0 mL container at 50.0 °C. The total pressure in the container was __________ atm.
6.78
A sample of a gas (5.0 mol) at 1.0 atm is expanded at constant temperature from 10 L to 15 L. The final pressure is __________ atm.
0.67
A flask contains a mixture of He and Ne at a total pressure of 2.6 atm. There are 2.0 mol of He and 5.0 mol of Ne in the flask. The partial pressure of He is __________ atm.
0.74
The volume occupied by 1.5 mol of gas at 35 °C and 2.0 atm pressure is __________ L.
19
A balloon originally had a volume of 4.39 L at 44 °C and a pressure of 729 torr. The balloon must be cooled to __________°C to reduce its volume to 3.78 L (at constant pressure).
0
The pressure of a sample of CH4 gas (6.022 g) in a 30.0 L vessel at 402 K is __________ atm.
0.414
CO (5.00 g) and CO2 (5.00 g) were placed in a 750.0 mL container at 50.0 °C. The total pressure in the container was __________ atm.
10.3
The reaction of 50 mL of Cl2 gas with 50 mL of CH4 gas via the equation: Cl (g) + CH (g) HCl (g) + CH Cl (g) 2 4 3 will produce a total of __________ mL of products if pressure and temperature are kept constant.
100
The reaction of 50 mL of N2 gas with 150 mL of H2 gas to form ammonia via the equation: N (g) + 3H (g) 2NH (g) 2 2 3 → will produce __________ mL of ammonia if pressure and temperature are kept constant.
100
A sample of gas (1.3 mol) occupies __________ L at 22 °C and 2.5 atm.
13
A sample of gas (24.2 g) initially at 4.00 atm was compressed from 8.00 L to 2.00 L at constant temperature. After the compression, the gas pressure was __________ atm.
16.0
The thermal decomposition of potassium chlorate can be used to produce oxygen in the laboratory. 3 2 2KClO (s) 2KCl (s) + 3O (g) → What volume (L) of O2 gas at 25 °C and 1.00 atm pressure is produced by the decomposition of 7.5 g of 3 2KClO (s) ?
2.2
SO2 (5.00 g) and CO2 (5.00 g) are placed in a 750.0 mL container at 50.0 °C. The partial pressure of SO2 in the container was __________ atm.
2.76
The molar volume of a gas at STP is __________ L.
22.4
A vessel contained N2, Ar, He, and Ne. The total pressure in the vessel was 987 torr. The partial pressures of nitrogen, argon, and helium were 44.0, 486, and 218 torr, respectively. The partial pressure of neon in the vessel was __________ torr.
239
The pressure in a 12.2 L vessel that contains 2.34 g of carbon dioxide, 1.73 g of sulfur dioxide, and 3.33 g of argon, all at 42 °C is __________ mmHg.
263
Standard temperature and pressure (STP), in the context of gases, refers to
273 K and 1 atm
A gas originally at 27 °C and 1.00 atm pressure in a 3.9 L flask is cooled at constant pressure until the temperature is 11 °C. The new volume of the gas is __________ L.
3.7
A sample of N2 gas (2.0 mmol) effused through a pinhole in 5.5 s. It will take __________ s for the same amount of CH4 to effuse under the same conditions.
4.2
The normal boiling point of the substance with the phase diagram shown above is __________ °C.
40
Which one of the following substances will have hydrogen bonding as one of its intermolecular forces?
5 Hs, 1 C, 1 N
A sample of O2 gas (2.0 mmol) effused through a pinhole in 5.0 s. It will take __________ s for the same amount of CO2 to effuse under the same conditions.
5.9
The reaction of 50 mL of Cl2 gas with 50 mL of CH4 gas via the equation: Cl (g) + C H (g) C H Cl (g) 2 2 4 2 4 2 → will produce a total of __________ mL of products if pressure and temperature are kept constant.
50
CO (5.00 g) and CO2 (5.00 g) were placed in a 750.0 mL container at 50.0 °C. The partial pressure of CO in the container was __________ atm.
6.31
Ammonium nitrite undergoes thermal decomposition to produce only gases: NH NO (s) N (g) + 2H O (g) 4 2 2 2 → What volume (L) of gas is produced by the decomposition of 35.0 g of NH4NO2 (s) at 525 ° C and 1.5 atm?
72
A sample of He gas (2.0 mmol) effused through a pinhole in 53 s. The same amount of an unknown gas, under the same conditions, effused through the pinhole in 248 s. The molecular mass of the unknown gas is __________ g/mol.
88
If 3.21 mol of a gas occupies 56.2 L at 44 °C and 793 torr, 5.29 mol of this gas occupies __________ L under these conditions.
92.6
The heating curve shown was generated by measuring the heat flow and temperature for a solid as it was heated. The slope of the __________ segment corresponds to the heat capacity of the solid.
AB
On the phase diagram , segment __________ corresponds to the conditions of temperature and pressure under which the solid and the gas of the substance are in equilibrium.
AC
On the phase diagram shown, the coordinates of point __________ correspond to the critical temperature and pressure.
B
The heating curve shown was generated by measuring the heat flow and temperature for a solid as it was heated. The slope of the __________ segment corresponds to the heat capacity of the liquid of the substance.
CD
Of the following substances, only __________ has London dispersion forces as its only intermolecular force.
CH4
In which of the following molecules is hydrogen bonding likely to be the most significant component of the total intermolecular forces?
CO2
The heating curve shown was generated by measuring the heat flow and temperature of a solid as it was heated. The heat flow into the sample in the segment __________ will yield the value of the ∆Hvap of this substance.
DE
Of the following substances, only __________ has London dispersion forces as the only intermolecular force.
Kr
The intermolecular force(s) responsible for the fact that CH4 has the lowest boiling point in the set CH , SiH , GeH , SnH 4 4 4 4 is/are
London dispersion forces
Of the following, ________ is a correct statement of Boyle's law
PV = constant
The first person to investigate the relationship between the pressure of a gas and its volume was
Robert Boyle
Which one of the following is a valid statement of Avogadro's law?
V = constant × n
Of the following, __________ is a valid statement of Charles' law.
V/T = constant
The phase diagram of a substance is given above. The region that corresponds to the solid phase is __________.
W
One significant difference between gases and liquids is that
a gas assumes the volume of its container
Gaseous mixtures
are all homogeneous
Hydrogen bonding is a special case of
dipole-dipole attractions
The vapor pressure of any substance at its normal boiling point is
equal to atmospheric pressure
An ideal gas differs from a real gas in that the molecules of an ideal gas
have no attraction for one another
A real gas will behave most like an ideal gas under conditions of
high temperature and low pressure
What intermolecular force is responsible for the fact that ice is less dense than liquid water?
hydrogen bonding
The phase diagram of a substance is given above. This substance is a __________ at 25°C and 1.0 atm.
liquid
The strongest interparticle attractions exist between particles of a __________ and the weakest interparticle attractions exist between particles of a
solid, gas
In liquids, the attractive intermolecular forces are
strong enough to hold molecules close but not strong enough to keep molecules from moving past each other
In general, the vapor pressure of a substance increases as __________ increases.
temperature
The kinetic-molecular theory predicts that pressure rises as the temperature of a gas increases because
the gases will collide more frequently and more energetically with the wall
