Exam 3 - Gas Lecture

Question 1

What is a gas?

Answer 1

A substance that has no defined volume or shape

Question 2

The volume and shape of a gas depend on…

Answer 2

…the size and shape of its container

Question 3

“Gases are highly compressible”; what does this mean?

Answer 3

When pressure is applied, the volume of a gas changes.

Question 4

Most of the volume of a gas is actually…

Answer 4

…empty space. Because of this, each gas molecule behaves as if no other molecules are present.

Question 5

Generally, gases are small molecules comprised of…

Answer 5

…nonmetals

Question 6

What is pressure?

Answer 6

The force exerted on a given unit area.

Question 7

What is the SI unit for pressure?

Answer 7

Newtons per square meter

Question 8

What is the most common English unit for pressure?

Answer 8

Pounds per square inch, or psi.

Question 9

What are the four variables used to describe a gas?

Answer 9

Pressure, amount, temperature, and volume. They are all interrelated.

Question 10

The mass of a 1 square meter cross-sectional volume of atmosphere has a mass of 10,000kg, which corresponds to…

Answer 10

100,000N

Question 11

Total pressure is also called…

Answer 11

…absolute pressure

Question 12

Difference of height is sometimes called…

Answer 12

…Pressure gage

Question 13

What is a barometer?

Answer 13

It is a device used to measure atmospheric pressure. The gases in the atmosphere exert pressure on the Hg, causing it to rise in the tube. The pressure is reported as the distanced the Hg moves up the tube. Under typical atmospheric conditions, the distance is approximately 760mm, or 30 inches.

Question 14

What is a manometer?

Answer 14

A device used to measure the pressure of a gas sample. It is similar to a barometer, but instead of one end being under a pol of Hg, it is attached to a gas sample.

Question 15

What are the relationship between pressure, temperature, amount, and volume?

Answer 15

Gas Laws

Question 16

What are the three Gas Laws?

Answer 16

Boyle’s law, Charle’s law, and Avogadro’s law.

Question 17

Boyle’s law…

Answer 17

…relates the volume of a gas to its pressure. At a constant temperature and with a fixed quantity of gas, pressure and volume are inversely related. (If we decrease the volume of a gas, its pressure increases)

Question 18

Charle’s law…

Answer 18

…It relates the volume of a gas to its temperature. The law states that at a constant pressure and with a fixed quantity of gas, temperature and volume are directly related.

Question 19

When dealing with gases, temperature needs to be in…

Answer 19

…Kelvin

Question 20

What is the Charle’s Law formula?

Answer 20

V1/T1 = V2/T2 (KELVIN)

Question 21

What is the Boyle’s Law formula?

Answer 21

P1V1=P2V2

Question 22

What is the Avogadro’s Law formula?

Answer 22

V1/n1 = V2/n2

Question 23

What is the Ideal Gas Law?

Answer 23

Pv=nRT (R is 0.08206)

Question 24

What is the combination between Charle’s and Boyle’s formulas that relates pressure, temperature, and volume of a sample of gas?

Answer 24

P1V1/T1=P2V2/T2

Question 25

What happens to the molecules of gas when they get bigger?

Answer 25

They start to deviate from standard behavior

Question 26

What type of mixture is formed when gases are mixed with other gases?

Answer 26

Homogeneous, ALWAYS!

Question 27

What is the law of partial pressures?

Answer 27

It is the pressure exerted by an individual component of a mixture, which is called partial pressure

Question 28

The overall pressure of a gas depends on:

Answer 28

The number of moles of gas, temperature and volume