Chapter 8: Gas Laws and the Mole

Question 1

Forces that hold particles together (3)

Answer 1

Van der Waal, dipole-dipole, hydrogen bonding

Question 2

Define diffusion

Answer 2

Diffusion is the spontaneous spreading out of a substance, and is due to the natural movement of its particles

Question 3

Define Boyle’s Law

Answer 3

At a constant temperature, the volume of a given mass of any gas is inversely proportional to the pressure of the gas

Question 4

Charles’ Law

Answer 4

At a constant pressure, the volume of a given mass of gas is directly proportional to the Kelvin temperature

Question 5

Gay-Lussac’s Law of Combing Volumes

Answer 5

There is a simple whole number ratio of volumes at constant temperature and pressure

Question 6

Avogadro’s Law

Answer 6

Equal volumes of gases under the same conditions of temperature and pressure, contain equal numbers of molecules

Question 7

Define mole

Answer 7

A mole of any substance is defined as the amount of substance that contains as many particles (atoms, molecules or ions) as there atoms of C12 in 12g of C12

Question 8

Define empirical formula

Answer 8

The empirical formula of a compound indicates what elements are present in the compound and the simplest whole number ratio in which the atoms of these elements are present

Question 9

Define ideal gas

Answer 9

An ideal gas is a gas that perfectly obeys all of the gas laws under all conditions of temperature and pressure

Question 10

Avogadro’s Constant

Answer 10

6x10 23 mol

Question 11

Define relative molecular mass

Answer 11

Relative molecular mass of a substance is the average mass of a molecule of the substance relative to one-twelfth of the mass of an atom of C12

Question 12

Define molar mass

Answer 12

The molar mass of a substance is the mass in grams of one mole of the substance

Question 13

Combined Gas Law ( Formula)

Answer 13

P1V1/T1 = P2V2/T2

Question 14

How to change degrees to kelvin

Answer 14

Add 273

Question 15

Kinetic Theory of Gases - 5 Assumptions

Answer 15

1. particle diameter negligible compared to distances between them
2. no forces between particles
3. constant rapid random motion
4. kinetic energy proportional to Kelvin temp
5. all collisions are perfectly elastic (untrue)

Question 16

When do real gases behave most like an ideal gas?

Answer 16

Room temp and pressures/high temp and low pressures

Question 17

Equation of state for an ideal gas

Answer 17

PV=nRT
(R=8.31 J K-1 mol-1)