Chemistry Ch. 10 and 11 Quiz

Convert each of the following into the unit specified. 125 mm Hg into atmospheres

1.64474 x 10^-1 atm

Give 2 examples of common substances that sublime at ordinary temperatures.

2 common substances that sublime are dry ice (solid CO2) and iodine.

Convert each of the following into the unit specified. .20 atm into pascals

2.0650 x 10^4 Pa

Convert each of the following into the unit specified.5.38 kPa into millimeters

4.03533 x 10

A gas has a volume of 450.0 mL. If the temperature is held constant, what volume would the gas occupy in the pressure were reduced to one-fourth of its original value?

450 ml * 4 = 1800 mL

How many moles are contained in each of the following STP?0.125 L Ne

5.58 ⋅ 10−3 mol Ne d. 3.13 ⋅ 10−3 mol NH3

The normal respiratory rate for a human being is 15.0 breaths per minute. The average human being is 15.0 breaths per minute. The average volume of air for each breath is 505 cm^3 at 20.0C and 9.95 x 10^4 Pa. What is the volume of air at STP that an individual breathes in one day? Give your answer in cubic meters.

9.98 m3/day

What is a pascal?

A pascal is the pressure exerted by a force of one newton (1 N) acting on an areaa of one square meter.

Explain how the attractive forces between the particles in a liquid are related to the equilibrium vapor pressure of that liquid.

If the equilibrium vapor pressure is higher, than the attractive forces between particles aren't as high.

a sample of gas is collected over water at the temperature of 35.0 C when the barometric pressure reading is 742.0 torr. What is the partial pressure of the dry gas?

P total = P gas + P H2O P total = 742.0 torr P H2O is 35.0 C = 42.2 torr ? 742 = P gas + 42.2 - 42.2 - 42.2 699.8 torr = P gas The partial pressure of the dry grass is 666.8 torr.

A gas has a volume of 450.0 mL. If the temperature is held constant, what volume would the gas occupy in the pressure were doubled?

P1 V1 = P2 V2 P1= 1 P2= 2 V1 = 450.0 mL V2 = x 1*450 = 2 * x 450 = 2 * x 225ml = x

What factors affect the rate of diffusion of one gas through another?

Some factors that can affect the rate of diffusion is the temperature and what type of gases they are. Depending on the temperature the molecules can either go faster or slower which can affect how they mix. Also, how heavy or light factors into the diffusion.

What is sublimation?

Sublimation is the change of state from solid directly to a gas.

What accounts for the difference in the heights of the mercury and water columns?

The density accounts for the differences in the heights of mercury and water.

Describe in your own words the process of diffusion.

The mixing of two gases without help.

How do gases compare with liquids and solids in terms of the distance between their molecules?

The molecules for gases are farther apart than liquids and solids. Gases take up 1000 times greater volume with the same numbers of particles in a gas or liquid state.

How are the volume and pressure of a gas at constant temperature related?

The pressure and the volume together equal a constant. If one increases, the other one decreases. This can be expressed by Boyle's law. PV = k

Explain why pressure increases as a gas is compressed into a smaller volume.

The pressure of a gas is caused by moving molecules hitting a container's walls. If the volume of a container is decreased but the same number of gas molecules is present at the same temperature there will be more molecules per unit, which means that the pressure increases as well.

Explain what is meant by the partial pressure of each gas within a mixture of gases.

The pressure of each gas in a mixture is the partial pressure.

What is the relationship between the temperature, speed, and kinetic energy of gas molecules?

The temperature can control the speed that the gas molecule is going, which in turn changes the kinetic-energy.

Identify three units used to express pressure.

The three units used to express pressure are pascal (Pa), atmosphere (atm), and Hg (torr).

How are the absolute temperature of a gas at constant volume of a gas at constant pressure related?

The volume changes by 1/273 of the original volume for each Celsius degree, at a constant pressure and initial temperature of 0 C.

A sample of gas at 47C and 1.03 atm occupies a volume of 2.20 L. What volume would this gas occupy at 107C and 0.789 atm?

V1 = 2.20 L T1 = 47 C + 273.15 = 320.15 K P1 = 1.03 atm V2 = x T2 = 107 C + 273 = 380.15 K P2 = 0.789 atm 1.03 atm (P1) 2.20 L(V1) = 0.789 atm(P2) x (V2) 320.15 K (T1) 380.15 K (1.03 atm) (2.2o L) (380.15 K) = (0.789 atm)( x) (320.15 K) (1.03 atm) (2.20 L) (380.15 K) = x Plug into calculator (0.789 atm)(320.15 K) V2 = 3.41024 L

When using the ideal gas law, why do you have to pay particular attention to units?

the units of volume, temperature, and pressure must match those of the gas constant used.

In what situations is the ideal gas law most suitable for calculations?

when three of the four variables P, V, T, and n are known

Calculate the pressure, in atmospheres, exerted by each of the following: c. 5.50 x 10^4 mL CO2 containing 2.15 mol at 75C

0.777 atm

Convert one atmosphere to millimeters of mercury.

1 atm is 760 mm torr.

What is an ideal gas?

An ideal gas is a gas where it's behavior obeys the kinetic molecular-theory of gases.

What is diffusion?

Diffusion is a spontaneous mixing of the particles of 2 substances caused by their random motion.

What is fluid?

Fluid is a substance that can flow and therefore take the shape of its container.

What is the idea the kinetic-molecular theory based on?

Kinetic-molecular theory is based on the idea that particles of matter are always in motion. It is used to explain properties of gases, liquids, and solids.

What is the SI equivalent of one standard atmosphere of pressure?

The SI equivalent of one standard atmosphere of pressure is 1.01325 x 10^5 Pa or 101. 325 kPa.

State the assumptions that the kinetic- molecular theory makes about the characteristics of gas particles.

The assumptions that the kinetic-molecular theory makes about the characteristics of gas particles are that gas particles are constantly moving and are completely elastic.

At a given temperature, what factor determines the rates at which different molecules undergo diffusion and effusion?

The factors that determines the rates at which different molecules undergo diffusion and effusion is volume and the weight of the gas.

State the assumptions that the kinetic- molecular theory makes about the characteristics of gas particles.

The first assumption is that gases consist of large numbers of tiny particles that are far apart relative to their size. The second assumption is Collisions between gas particles and between particles and between particles and container walls are elastic collisions. The third is gas particles are in continuous, rapid, random motion. The fourth is that there are no forces of attraction between gas particles. And the fifth is that the temperature of a gas depends on the average kinetic energy of the particles.

What is it meant by the normal freezing point of a substance?

The freezing point of a substance is the temperature at which the solid and liquid are in equilibrium at 1atm (760 torr, or 101.3kPa) pressure.

Why does gas in a closed container exert pressure?

The gas exerts more pressure because the molecules' collisions increase causing an outward push against the walls. Gas molecules exert pressure on any surface they collide into.

Why does a column of mercury in a tube that is inverted in a dish of mercury have a height of about 760 mm at sea level?

The height depends on the weight of the water compared to the weight of the air. It was at the height of 760 mm at sea level because it is 14 times more dense than water and could be raised only 1/14th as high as water.

The density of water is approximately 1/13.5 the density of mercury. What height would be maintained by a column of water inverted in a dish of water at sea level?

The height that would be maintained by the water would be 705.714 mm at sea level.

How are the pressure and absolute temperature of a gas at constant volume related?

They are directly proportional.

How do the partial pressures of gases in a mixture affect each other?

They don't affect each other. They only create more pressure.