Chemistry - Unit 7

Water could be made to boil at 105°C instead of 100°C by

increasing the external pressure

Which of the following best describes the motion of the particles in a piece of steel?

all are moving

Which substance is most volatile at 50°C

allylamine boiling point 52.23°C

How does the atmospheric pressure at altitudes below sea level compare with atmospheric pressure at sea level?

the atmospheric pressure below sea level is higher

Standard conditions when working with gases are defined as

0°C and 101.3 kPa

What volume of oxygen gas (O2) can be produced from the decomposition of 15.0 g of potassium nitrate at 27 °C and 1.1 atm? Using the following equations.

1.7L

Idk what the question is

150 K

The volume of a gas is 250 mL at 340.0 kPa pressure. What will the volume be when the pressure is reduced to 50.0 kPa, assuming the temperature remains constant?

1700 mL

A breathing mixture used by deep-sea divers contains helium, oxygen, and carbon dioxide. What is the partial pressure of oxygen at 101.4 kPa if PHe = 82.5 kPa and PCO₂ = 0.4 kPa?

18.5kPa

Suppose 250 mL of H2 is collected at 202.6 kPa and 287K. What is the new volume at STP?

476 mL

The pressure in Denver is measured to be 98.0kPa. What height of mercury will be measured in a barometer at this altitude?

735 mm Hg

What is the normal boiling point of ethanol?

78 C

What volume does 14 g of CO2 gas occupy at 1 atm and 315K?

8.3 L

The triple point is labeled point:

D

Consider an iron cube and an aluminum cube. If the two cubes were at the same temperature, how would the average kinetic energy of the particles in iron compare with the average kinetic energy of the particles in aluminum?

There would be no difference in the average kinetic energies.

When the vapor pressure of a liquid is equal to the pressure above it in a closed container, the liquid

begins to boil

Which of the following gases will effuse the most rapidly?

hydrogen

If a sealed syringe filled with air at room temperature is plunged into cold water, what will happen to the size of the gas bubble?

it decreases

What happens to the temperature of a liquid as it evaporates?

it decreases

Which of the following statements is not true, according to the kinetic energy?

only particles of matter in the gaseous state are in constant motion

Which of the following represents an inverse relationship?

pressure versus volume

What causes gas pressure in a container such as helium balloon?

the collision of molecules with the walls of the container

A rigid, sealed container holds 2.0 L of nitrogen gas at 273 K & 1 atm. How will the pressure change if the container is heated?

the new pressure will be greater than 1 atm

During the pop can experiment, how does the pressure inside the can compare to the outside pressure once the can is flipped over into the larger beaker of water?

the pressure inside the can is less than the pressure outside the can

Why is a gas easier to compress than a liquid or a solid?

there is more empty space in an gas

The substance is initially at 1.0 atm and 75 °C. It is heated to 120°C while the pressure is held constant. What phase change takes place?

vaporization

Which of the following will evaporate the fastest?

water at 40°C