Amount of Substance

Question 1

What does ‘One mole of a substance’ refer to?

Answer 1

The amount that contains the same number of particles as there are in atoms in exactly 12g of Carbon-12.

Question 2

What does ‘Avogadro’s constant’ refer to?

Answer 2

The number of particles in one mole of a substance.

Question 3

What is Avogadro’s constant?

Answer 3

6.02x10²³

Question 4

What does ‘Molar mass’ refer to?

Answer 4

The mass of a substance that contains one mole of that substance.

Question 5

What does ‘Molar gas volume’ refer to?

Answer 5

The number of moles of gas in 1dm³

Question 6

How do you work out Molar Mass?

Answer 6

Molar mass= Mass (g) / Moles

Question 7

How much does one mole of any gas at room temperature and pressure occupy?

Answer 7

24dm³ or 24000cm³

Question 8

What are the steps to work out the Empirical Formula?

Answer 8

1. Divide both masses by the relative atomic masses.
2. Write this as a ratio and simplify that.
3. Write this ratio as a formula.

Question 9

What are salts that contain water of crystallization called?

Answer 9

Hydrated salts.

Question 10

What are salts that don’t contain water of crystallization called?

Answer 10

Anhydrous salts.

Question 11

What does the dot in hydrated salts mean? (E.G.
CuSO4.5H2O)

Answer 11

That everything after the dot will be given off first if the substance is heated.