Give two examples each of instantaneous reactions,slow reactions and moderate speed reactions????

Instantaneous reactions are those which proceed with a very fast speed. Examples are

1) The reaction between a strong acid and a strong base

 HCl + NaOH  ------------> NaCl + H₂O

2) The reaction of NaCl and AgNO₃. This is an example of precipitation reaction. When an aqueous solution of NaCl is mixed with a solution of AgNO₃, a white precipitate of AgCl is formed.

 NaCl + AgNO₃  ------------> NaNO₃ + AgCl ↓

Moderate reactions proceed with measurable speed and hence their rate of reaction can be measured easily. For example

1) The decomposition of Dinitrogenpentaoxide dissolved in CCl₄ solution.

 2N₂O₅ ------------> 4NO₂ + O₂

2) The hydrolysis of an ester

Slow reactions are those which proceed at very slow speed. For example

(1) Rusting of iron

(2) The reaction between hydrogen gas and chloride gas to form hydrogen chloride (only in dark)

 H₂ (g) + Cl₂ (g) ---------> 2HCl (l)  (in dark)