Chapter 6: Chemical Formulae and Equations

Question 1

What are the substances that have the state symbol aq (aqueous)?

Answer 1

Acids, alkalis and soluble salts,
Halogens if water is present.

Question 2

What are the substances that have the state symbol s (salt)?

Answer 2

Insoluble salts

Question 3

How do you derive the chemical formula of compounds?

Answer 3

Criss cross the valencies of the elements

Question 4

What is the process of writing an ionic equation?

Answer 4

1. Block out substances that do not ionise (s, l, g, halogen aq)
2. Break down aq compounds in terms of ions
3. Cancel the repeats if they appear in both sides of the equation (before and after the arrow)
4. Rewrite the ionic equation with the leftover ions and their charges and include the ‘blocked’ substances from the start