Topic 5 - 5.3 - Water/Neutral solutions

Question 1

What does the term equibrilium refer to?

Answer 1

When there is no net change in concentration of reactants and products (present in all aqueous solutions)

Question 2

What will adding water do to an acid or base do?

Answer 2

Reduces the concentration of ions in the solution.

Question 3

Describe the dissociation of water into hydrogen and hydroxide ions:
* using an equation
* WITHOUT using an equation

Answer 3

• H₂O ⇌ H⁺ + OH⁻ (reversible)
• A small proportion of water molecules break up to form hydrogen ions and hydroxide ions.
  Some of these ions react together again to form water molecules, therefore making this reaction reversible.

Question 4

What is the pH of water/neutral solutions? Explain why this is.

Answer 4

• exactly 7 (neutral)
• the concentration of hydrogen ions is equal to the concentration of hydroxide ions.

Question 5

What does the presence of ions mean for water?

Answer 5

The presence of ions means that water can conduct electricity but not very well. This is because only a small proportion of water molecules actually dissociate.