Question

Give two example of each of a chemical characterised by :- evolution of gas

Answer 1

Answer:

i) Evolution of gas--- Reaction between zinc and dilute sulphuric acid

ii) Change in color--- Reaction between citric acid and purple colored potassium permanganate solution gives colourless solution.

iii) Formation of precipitate--- Reaction between potassium iodide and lead nitrate forms a yellow precipitate of lead iodide.

iv) Change in temperature: Reaction between zinc granules and dliute hydrochloric acid.

v) Change in state: Combustion of candle wax is characterized by a change in state from solid to liquid and gas.