ch 8

Question 1

1-5 Describe the 5 characteristics of gasses

Answer 1

1. rapidly moving particles.
2. have no attractive/repulsive forces.
3. particles are far apart
4. have small volumes compared to the volume of the container they occupy
5. their kinetic energies increase with temp increase.

Question 2

1. What are the units for measuring pressure?
2. How many mmHg or torr are there for each atm?
3. What is the determining factor for the kinetic rate of motion and energy for gas particles?
4. how do we calculate temp?
5. How do we express amount or quantity of gas?

Answer 2

1. atm, mmHg, torr, pascal (Pa), or psi
2. 760mmHg or 760 torr = 1atm.
3. Temp.
4. temp must be converted to K for any calculations. Convert back for answer if it is needed in Celsius. But always use K for temp calculations
5. in grams or in moles (n)

Question 3

1. T or F, the volume of a gas is equal to the volume of the container it is in?
2. will gas volume increase or decrease with an increase of temp?

Answer 3

1. T

2. increase

Question 4

1. When the temp of gas decreases the molecules have ………….. collisions.
2. When temp increases the molecules have …………. collisions.
3. what is atmospheric pressure? Does it decrease or increase when altitude increases?
4. What is the barometric pressure at sea level? Does barometric pressure raise or fall when it’s hot? Rain?

Answer 4

1. fewer
2. more
3. is the pressure exerted on us by the gas particles in the air. It decreases with greater altitude
4. 1 atm. It rises with heat. It decreases with rain

Question 5

1. Boyles law?
2. What is the formula for Boyles law?
3. What must be held constant for this formula to work?

Answer 5

1. PV pressure of a gas is inversely related to volume. If volume increases, pressure decreases.
2. P1 V1 = P2 V2
3. Temp and amount

Question 6

1. Charles law?
2. What is the formula for charles law, TV?
3. What must be held constant for this formula to work?

Answer 6

1. TV temp and volume have a direct relationship. If temp increases, so does volume
2. V1/T1 = V2/T2
3. Pressure and amount

Question 7

1. Pressure ……….. when volume decreases.

2. When T decreases, V ……………. .

Answer 7

1. increases

2. decreases

Question 8

1. Gay Lussac’s Law?
2. What is the formula for Gay Lussac’s Law TP?
3. What must be held constant for this formula to work?

Answer 8

1. TP temp is directly related to pressure. Temp goes up, so does pressure.
2. P1/T1 = P2/T2
3. Volume and amount

Question 9

1. What is the combined gas law formula?

2. What is always important to remember about temp?

Answer 9

1. PVT P1V1/T1 = P2V2/T2

2. Temp always is calculated in K.

Question 10

1. What is Avogadro’s Law (concerning gasses)?
2. What is the formula for avogadro’s law VN?
3. Can we add moles to the combined gas law? What would the formula look like?

Answer 10

1. VN the volume of gas is directly related to the number of moles (n). The more moles, the more volume.
2. V1/n1 = V2/n2
3. V1 P1/n1 T1 = V2 P2/n2 T2

Question 11

1. What is STP?
2. Why is this useful?
3. What is molar volume?

Answer 11

1. Standard Temp and Pressure
   0 Celsius or 273K and 1atm or 760mmHg
2. We can compare the volumes of various gasses at STP.
3. At STP 1 mole of gas = 22.4L

Question 12

1. What is Dalton’s Law?

2. What is the formula for this law?

Answer 12

1. Law of partial pressures. The pressure that each gas in a mixture exerts adds up to the total pressure.
2. PT= P1+P2+P3 …….

Question 13

1. What is the total pressure of the air we breathe?

Answer 13

1. 760mmHg or 1 atm