Acids and redox
Explain the difference between acids, bases and alkalis.
Acids dissolve in water and release H+ ions in aqueous solution. They are proton donators. A base neutralises an acid to form a salt. Alkalis are water-soluble bases that dissolve in water to release OH– ions in aqueous solution. These are proton acceptors.
What makes an acid weak or strong?
A strong acid releases all its hydrogen atoms as H+ ions and completely dissociates / ionises. Weak acids only release a small proportion of its hydrogen atoms as H+ ions and partially dissociates.
Give the ionic formulae for sulphate, carbonate, nitrate, hydroxide, ammonia, zinc and silver.
Give the formula for hydrochloric acid, sulphuric acid, nitric acid, and ethanoic acid.
Give the formula for sodium hydroxide, potassium hydroxide, and ammonia.
Give the neutralisation formula.
H+ and OH– to form H2O.
Acid + Base = Salt + Water (+ Carbon Dioxide if the base was a carbonate)
A base can include metal carbonates, metal oxides, metal hydroxides and ammonia.
Define the term salt.
When the H+ in an acid is replaced by a metal ion.
Give the products of a reaction with an acid and a carbonate.
General equation: Acid + carbonate –> _salt_ + __H20__ + ___CO2__
Give the products of a reaction with an acid and a metal oxide.
General equation: Acid + metal oxide (base) –> _salt_ + __H20__
Give the products of a reaction with an acid and ammonia.
General equation: Acid + metal oxide (base) –> _ammonium_ + __H20__
Give three reasons titrations are used.
- Find the concentration of a solution
- Identify unknown chemicals
- Find the purity of a substance