4.4.3 - Moles Ratios In Formulae

Question 1

What is the empirical formula of a substance !?

Answer 1

. The simplest mole ratio of its elements

Question 2

How do you calculate the empirical formula of a substance !?

Answer 2

. Mass, RFM, moles, ratio(divide by smallest) table

Question 3

How do you calculate the molecular formula!?

Answer 3

. Using the empirical formula and the RFM
(Uncancelled multiple of the empirical formula with the correct RFM)

Question 4

What is water of crystallisation!?

Answer 4

. Hydrated Salt crystals contain water trapped inside them in a fixed mole ratio
(CuSo^4 . XH^2O)

Question 5

How is The mole ratio written in water of crystallisation!?

Answer 5

. 1:X

Question 6

How do you calculate water of crystallisation !?

Answer 6

. From the masses of salt and water produced on heating
1. Calculate mass of water lost
2. Draw a mass, RFM, moles, (➗by smallest) table