Types of reactions (B): swapping partners and electrons
Answers are for parents and teachers.
1
Write the neutralisation of nitric acid, HNO₃, with potassium hydroxide, KOH. Name the salt.
HNO₃ + KOH → KNO₃ + H₂O; the salt is potassium nitrate.
2
Draw the colour order of a universal indicator from strong alkali to acid.
Violet, (blue-green), green, yellow, orange, red.
3
In Ca → Ca²⁺ + 2e⁻, is calcium oxidised or reduced? How many electrons do 3 Ca atoms lose?
Oxidised; 3 × 2 = 6 electrons.
4
A friend says the oxidising agent is the substance that is oxidised. Is that right?
No. The oxidising agent gains electrons, so it is reduced.
5
A grown-up pours a little vinegar on a pinch of baking soda in an open cup. Write the word equation of what you see.
Acid + carbonate → salt + water + carbon dioxide.