Reactions of Acids

What is the general equation for a neutralisation reaction?

Base + acid ⟶ salt + water

What is the general equation for the reaction between metal carbonate and acid?

Metal carbonate + acid ⟶ salt + water + carbon dioxide

What is the general equation for the reaction between metal oxides and acids?

Metal oxide + acid ⟶ a salt + water

How is a soluble salt formed?

1. React the excess acid with some insoluble chemical (e.g., metal oxide).

2. Filter off the leftovers.

3. Crystallise the product

What do acids produce in aqueous solutions?

Acids produce hydrogen ions (H⁺).

What do alkalis produce in aqueous solutions?

Alkalis produce hydroxide ions (OH^-).

What are bases, acids and alkalis?

Bases are compounds that neutralise acids.

What is an acid?

Acids produce hydrogen ions in aqueous solutions.

What is an alkali?

Alkalis are soluble bases - produce hydroxide ions in aqueous solutions

What is the pH scale and what does a pH of 7 show?

The measure of acidity/alkalinity of a solution; pH of 7 is a neutral solution

State the general equation for a neutralisation reaction in a short, ionic form.

H⁺ + OH^- ⟶ H₂O

What is a strong acid?

A strong acid is completely ionised in aqueous solution.

What is a weak acid?

A weak acid is only partially ionised in aqueous solution.

What happens to pH as concentration of H⁺ increases?

The pH decreases

What is a concentrated acid?

Concentrated acid has more moles of acid per unit volume than dilute.

What is a dilute acid?

A dilute acid has less moles of acid per unit volume than concentrated. 

Is a concentrated/dilute acid the same as a strong/weak acid?

Concentration is not the same thing as strength of an acid. Strength refers to whether the acid is completely ionised in water (strong) or only partially ionised in water (weak).

As the pH is decreased by one unit, what change is seen in the hydrogen ion concentration?

Increases by a factor of 10

Name the following salts: LiNO₃, K₂CO₃, MgBr₂, BaSO₄

Lithium nitrate, Potassium carbonate, Magnesium bromide, Barium sulfate