Amount Of Substance

Question 1

What is the amount of substance?

Answer 1

The number of chemical species the substance contains (mol)

Question 2

What is Avogadros constant?

Answer 2

The number of carbon atoms in 12g of carbon-12.

Question 3

What is a mole?

Answer 3

The amount of any substance containing as many particles as there are carbon atoms in 12g of carbon 12

Question 4

How do you work out the number of particles?

Answer 4

=n x Na

Mol X avagadros constant

Question 5

What is the molar mass (M)?

Answer 5

The mass of 1 mole of a substance gmol-1

Relative molecular mass/atomic mass in Grams

Question 6

Equation to work at moles using mass?

Answer 6

n=m/M

Question 7

What is the empirical formula?

Answer 7

The simplest whole number ratio of atoms of each element within a compound

Question 8

What is the molecular formula?

Answer 8

The actual number of atoms of each element within a compound

Question 9

What is the equation to work out the molecular formula?

Answer 9

Relative molecular mass/ relative empirical mass

Then X by the empirical formula

Question 10

What is Avogadro’s hypothesis?

Answer 10

Equal volumes of gases at the same temperature and pressure contain equal numbers of particles

Question 11

What is the Molar Volume?

Answer 11

The volume of one mole or gas and is the same for all gases at the same temp and pressure (24.0 dm3, 24000cm3)

Question 12

How do you work out the moles of a gas at RTP?

Answer 12

n= V(dm3)/ 24.0

Question 13

What is the ideal gas equation?-include all units

Answer 13

pV=nRT
p- pressure (Pa)
V- volume (m3)
n- moles (mol) 
R- gas constant 8.314 JK-1mol-1
T- temp (K) (+273)

Question 14

What is an ideal gas?

Answer 14

1. Volume of molecules in negligible compared to size of container
2. No intermolecular forces between separate molecules, widely separated
3. Collisions are elastic so kinetic energy of molecules remain constant
4. Molecules move continuously and randomly

Question 15

What is the ideal gas equation using Mr?

Answer 15

pV=mRT/Mr

Question 16

What graphs show the gas laws in pV=nRT?

Answer 16

Volume-Temp= directly proportional 
Pressure-Temp= directly proportional 
Volume-Pressure= as 1 increases the other decreases

Question 17

What is the concentration?

Answer 17

Amount of solute(mol) is dissolved per 1dm3 of solution. Moldm-3

Question 18

How do you work out the mole of a solution?

Answer 18

n=CV

Question 19

What equation do you use to convert moldm-3 to gdm-3? And vice versa

Answer 19

m=nM

n=m/M

Question 20

What is the percentage yield?

Answer 20

The measure of efficiency of a reaction in terms of how much of the desired product is made

Question 21

What is the equation for percentage yield?

Answer 21

Actual(mol)of desired product/ max(mol) of desired product X100

Question 22

What is atom economy?

Answer 22

Measure of how much of the products are useful

Question 23

How do you work out atom economy?

Answer 23

Sum of Mr of desired product/ sum of Mr of all products X100

Question 24

What do you need to consider when calculation sum of Mr for atom economy?

Answer 24

The reaction ration (how many moles)