GASES

The following are observed characteristics of gases except for

• gases can be compressed by application of pressure

• gases diffuse and spontaneously mix with each other

• pressure exerted by a gas decreases with increase in temperature

• there is negligible attraction between particles of an ideal gas

The standard pressure of the atmosphere at sea level is

• 1 atm

• 760 torr

• 760 mm Hg

• all of the above

As altitude increases, air becomes less dense and

• pressure increases

• pressure decreases

• pressure remains the same

• none of the above

Raising the temperature of an enclosed gas

• slows down the kinetic energy of the gas molecules

• decreases the momentum of the gas molecules

• forces the gas particles to collide with the walls harder

• decreases the volume of the gas

At constant temperature and pressure, the rate of diffusion of a gas varies

• inversely as its density

• directly as its molecular mass

• directly as the square root of its density

• inversely as the square of its molecular mass

What are the standard temperature and pressure (STP) conditions for gas law problems?

• 760 atm, 0 °C

• 1 mm Hg, 273 °C

• 760 mmHg, 273 K

• 760 atm, 0 K

If the temperature of a confined gas is doubled, while the volume is held constant, what will happen to the pressure?

• it will be doubled

• it will be half as large

• it will be four times as large

• cannot be determined

What happens to the volume of a fully inflated balloon when it is taken outside on a cold day?

• its volume decreases

• it remains the same

• its volume increases

• its volume becomes equal to zero

The process by which a gas under pressure escapes from a compartment of a container to another by passing through a small opening is called

• effervescence

• effusion

• diffusion

• sublimation

As a bubble of air rises from a diver’s helmet to the surface of the water, it continuously expands. What law is illustrated?

• Dalton’s law

• Avogadro’s law

• Boyle’s law

• Charles’ law