3.1.2 Amount of Substance

Question 1

What is the relative atomic mass (Ar)?

Answer 1

Relative atomic mass (Ar) is the average mass of one atom compared to one twelfth of the mass of one atom of Carbon-12

Question 2

What is relative molecular mass (Mr)?

Answer 2

Relative molecular mass (Mr) is the average mass of a molecule compared to one twelfth of the mass of one atom of Carbon-12

Question 3

What is a mole?

Answer 3

A mole is the amount of substance in grams that has the same number of particles as there are atoms in 12 grams of Carbon-12

Question 4

How do you work out the number of moles for pure solids and gases?

Answer 4

Moles = mass/Mr

Question 5

How do you work out the number of moles for gases?

Answer 5

PV = nRT

Question 6

How do you work out the number of moles for solution?

Answer 6

Moles = C*V/1000

Question 7

How do you convert from degrees Centigrade to Kelvin?

Answer 7

Kelvin = centigrade + 273

Question 8

What is R - gas constant?

Answer 8

Gas constant = 8.31

Question 9

How do you convert from cm3 to m3?

Answer 9

cm3 * 10^-6 = m3

Question 10

How do you convert from m3 to cm3?

Answer 10

m3/10^-6 = cm3

Question 11

How do you convert from cm3 to dm3?

Answer 11

cm3/1000 = dm3

Question 12

How do you convert from dm3 to cm3?

Answer 12

dm3 * 1000 = cm3

Question 13

How do you convert from cm3 to m3?

Answer 13

cm3/1000,000 = m3

Question 14

How do you convert from m3 to cm3?

Answer 14

m3 * 1000,000 = cm3

Question 15

How do you convert from dm3 to m3?

Answer 15

dm3/1000 = m3

Question 15

How do you convert from dm3 to m3?

Answer 15

dm3/1000 = m3

Question 16

How do you convert from m3 to dm3?

Answer 16

m3*1000 = dm3

Question 17

What is apparatus uncertainty?

Answer 17

apparatus uncertainty = error value/measurement * 100

Question 18

What is the empirical formula?

Answer 18

An empirical formula is the simplest ratio of atoms of each element in the compound

Question 19

What is the ideal gas equation?

Answer 19

pV = nRT

Question 20

What does p stand for in the ideal gas equation and what are the units for it?

Answer 20

p = pressure (Pa)

Question 21

What does V stand for in the ideal gas equation and what are the units of?

Answer 21

V = volume of gas (m3)

Question 22

What does n stand for in the ideal gas equation?

Answer 22

n = number of moles

Question 23

What does R stand for in the ideal gas equation and what is it’s value?

Answer 23

R = gas constant (8.31)

Question 24

What does T stand for in the ideal gas equation and what are the units for it?

Answer 24

T = temperature (K)

Question 25

What is the molecular formula?

Answer 25

The molecular formula is the actual number of atoms of each element in a compound

Question 26

What is the total apparatus of an experiment?

Answer 26

Total apparatus uncertainty = Sum of all equipment apparatus uncertainty

Question 27

How do you reduce apparatus uncertainty?

Answer 27

• Take a bigger measurement

Question 28

Why is there a theoretical yield?

Answer 28

• Theoretical yield tales into account complete reaction, all of substance reacting. In reality, not all of substance reacts