Unit 9: Combined Gas Law

Describes the intensity of a force; the force per unit area that is applied on the surface of an object

Ex: F = 100N A=0.1m² = 1000 Pa

Pressure

A measure of how much the volume of matter decreases under pressure

Ex: Liquid is not easily _______ but gas is.

Compressible

The volume of a sample of gas changes with temperature and pressure; reference point for the moral volume of an ideal gas

Ex: 1 atm or 0 degree C

Standard Temperature and Pressure

How do gas particles create pressure in a container?

The gas particles are in constant motion. Particle collisions with the walls of the container creates pressure.

How does the volume of space between gas particles compare to the volume of individual gas particles?

The volume of space between gas particles is much larger than the volume of the gas particles themselves. We can ignore the volume of the gas particles.

What do you think would happen to the kinetic energy or gas particles if the temperature decreased?

The motion and kinetic energy would decrease as well.

What happens to the movement of gas particles when the kinetic energy of the gas particles is increased?

The motion and kinetic energy increase as well

If a gas particle comes close to another gas particle, will the particles be attracted to one another?

No, gas particles do not attract or repel one another

Describes the behavior of gas particles

• The volume of the space between gas particles is much larger than the volume of the gas particles themselves

• Gas particles do not attract or repel one another

• Gas particles are in constant motion - collisions between gas particles and the walls of a container creates pressure

• The motion and kinetic energy of gas particles increases as the temperature increases

Kinetic Molecular Theory

Kelvin Formula:

K = C + 273

Celsius Formula:

C = K - 273

75 C =

348 K

353 K =

79 C

• 273 K

• 1 atm

• These are the conditions that are most commonly used when testing gases

Standard Temperature and Pressure

What is the law?

• Pressure and Volume

• P and V have an inverse relationship

• Gas experiences a change

Boyle’s Law

Boyle’s Law equation:

P1 x V1 = P2 x V2

What is the law?

• Volume and temperature

• V and T have a direct relationship

• Gas experiences a change

Charles Law

Charles Law Equation:

V1/T1 = V2/T2

At 1.70 atm, a sample of gas takes up 4.25L. If the pressure on the gas is increased to 2.40 atm, what will the new volume be?

3.01 L

A balloon takes up 625L at 0C. If it is heated to 80C, what will the new volume be?

808L

Combined Gas Law Formula:

P1 x V1 / T1 = P2 x V2 / T2

A 40.0L balloon is filled with air at sea level (1 atm and 25 degrees C). It’s tied to a rock and thrown in a cold body of water, and it sinks to the point where the temperature is 4.0C and the pressure is 11.00 atm. What will its new volume be?

3.38L

A sample of CO at 42.09 K experiences a change in volume from 5499.2 cm³ to 781.4 cm³. If its new pressure is 7.6978 atm at 538.68K, what was its original pressure in atmosphere?

1.8546 atm

The temperature of a 25.67L sample of Rn is changed, causing a change in pressure from 375.76 kPa to 688.61 kPa. If its new temperature is 540.23C and its new volume is 29.179L, what was its original temperature in degrees Celsius?

117.4 degrees Celsius

Classify the elements

Diagrams

A student measures the pressure and volume of an empty water bottle to be 1.4 atm and 2.3 L. She then decreases the pressure to 0.65 atm. What is the new volume?

5.0 L

What is a result of neutral Carbon atom gaining two electrons?

Carbon with a negative two charge (C^-2)

What is not a compound?

CI

You have a gas that has a pressure of 2 ATM and a volume of 10 L. What would be the new volume if the pressure was changed to 1 ATM?

20 L

Identify the number of protons, neutrons, and electrons of Mg^+2

Protons = 12 Neutrons = 12 Electrons = 10

Identify the type of chemical reaction: 2C2H6 + 7O2 = 4CO2 + 6H2O

Combustion

Identify the type of chemical reaction: C + O2 = CO2

Synthesis

A student’s measured length during a science experiment was 12.00 cm. The actual size was 14.25. What was the percent error?

15.79%

Identify the type of chemical reaction: PbSO4 + FeO = PbO + FeSO4

Double Replacement

Identify bullseyes for accuracy and precision

The air is _________

A homogenous mixture

If a hairspray can is heated, what can be expected of the pressure of the gas inside the can?

The pressure will increase

A sample of gas with a volume of 30.0 mL at 25.0C is heated to 50.0C. What is the new volume of the gas?

32.5 mL

If a neutral atom of Carbon gains or loses electrons it is now classified as

An ion

What is 50C in Kelvin?

323

Gases have …

No definite shape or volume

The law of conversation of mass states that ___________

The mass of a chemical reaction remains constant

32.9 km = _______ cm

3,290,000

What would increase the gas pressure of a system?

a. Decrease the volume

b. Pump in more gas

c. Increase the temperature

In order to convert to Kelvin, you add _____ to the Celsius measurement

273

What is an isotope of Carbon?

Carbon - 16

____________ are the substances that are produced in a chemical reaction

Products

What is the pressure of a car tire that had an initial pressure of 1.8 atm but was heated from 38C to 123C?

2.3 atm