Empirical and molecular formulae

What is the difference between empirical and molecular formulae?

Were you able to work out the empirical formulae of all the examples presented?​ (a)   ​ (b)   ​ (c)   ​ (d)  

• Yes
• No
• I'm not sure what to do
• I need more practice

Use the way the water of crystallisation was worked out in this video to determine the water of crystallisation of the compound used in our practical. What is the (dot) formula of the compound you've analysed in lesson?