Moles, Solids & Gases

Question 1

Ideal gas equation calculating molar mass of gases and volatile liquids

Answer 1

PV = nRT

Question 2

Rearranging ideal gas equation

Answer 2

P = nRT/V pressure in Pa (Nm^-2)
V = nRT/P volume in m^3 
n = PV/RT amount of substance in moles
R = 8.31 JK^1mol^-1 gas constant
T = PV/nR temperature in K

Question 3

Converting units of pressure

Answer 3

1Pa = 1Nm^-2
1kPa = 1000Pa (x1000)
100kPa = 1atm = 100 000Pa

Question 4

Converting units of volume

Answer 4

1000cm^3 = 1dm^3
1000dm^3 = 1m^3 = 1 000 000cm^3

Question 5

Converting units of temperature

Answer 5

°C > K = +273

K > °C = -273

Question 6

Measurement uncertainty def + work out

Answer 6

The precision of any individual piece of apparatus. It is + or - half of the minimum scale

Question 7

% uncertainty eq

Answer 7

= (uncertainty / measurement) x 100 x number of measurements

Question 8

Volume of gas eq

Answer 8

V = n x 24
n = V / 24

Question 9

Why do you isotopes have similar chemical reactions?

Answer 9

They have the same number of protons and electrons

Question 10

How do you obtain a pure dry crystal from a solution?

Answer 10

Slowly heat it to allow it to evaporate and dry on filterpaper