EL6a - Moles and Masses

Question 1

What is the relative atomic mass?

Answer 1

The average of the isotopes of an element

(%a x mn) + (%a x mn) / 100

Question 2

What is the relative formula mass (Mr)

Answer 2

The relative formula mass of a compound is the sum of the relative atomic masses of the atoms in the numbers shown in the formula.

Question 3

What is Mr?

Answer 3

Relative formula mass

Question 4

What is the units of relative formula mass?

Answer 4

There are none - it is relative

Question 5

What is the Mr of CH4

Answer 5

16

Question 6

What is the Mr of 2CH4?

Answer 6

Still 16 as we don’t use big numbers

Question 7

What is Ar? (Not the element)

Answer 7

Relative atomic mass

Question 8

12g Carbon is how many moles?

Answer 8

1

Question 9

How many grams of Oxygen is in 1 mole of oxygen atoms?

Answer 9

16

Question 10

What is avogrado’s number?

Answer 10

6.02 x 10^23

Question 11

What is the equation for moles?

Answer 11

Number of moles = mass/relative atomic mass

Question 12

What is the formula for mass from moles and Mr?

Answer 12

Mass (g) = number of moles x Mr

Question 13

What is molar mass measured in?

Answer 13

g/mole

Question 14

What is molar mass?

Answer 14

How many grams of a substance are in one mole of it