redox

Question 1

Explain how oxides of nitrogen are formed in engines.

Answer 1

reaction of nitrogen and oxygen from the air
at high temperatures

Question 2

State the meaning of the term heterogeneous catalyst.

Answer 2

Catalyst in different phase which speeds up reaction without being used up

Question 3

Give two half-equations to show the oxidation and reduction processes that occur in this
redox reaction

Answer 3

Oxidation:
Cl2 + 2H2O → 2HClO + 2H+ + 2e–

Reduction:
Cl2 + 2H+ + 2e– → 2HCl

Question 4

Chlorine is reacted with cold, aqueous sodium hydroxide in the manufacture of bleach.
Give an equation for this reaction between chlorine and sodium hydroxide

Answer 4

2NaOH + Cl2 → NaCl + NaClO + H2O