Question

A student takes an unknown solution A.she observes that it does not turns blue litmus to red and give no effervescence with sodium hydrogen carbonate. however,a gas is evolved,when it reacts with zinc metal. 1>Identify the unknown Solution A. 2>Name the gas evolved. write the equation also.

Answer 1

the unknown solution is sodium hydroxide and the gas evolved is hydrogen gas
the reaction is:
2NaOH+Zn = Na2ZnO2 +H2

Answer 2

(1) The unknown solution is sodium hydroxide.

(2) The gas which evolves from it is hydrogen.

The reaction can be summarised here as 2NaOH+Zn = Na2ZnO2 +H2.

Sodium hydroxide is a potent caustic base and alkali which decomposes proteins even at ordinary temperatures and it may also cause serious chemical burns.

However, it is soluble in water and it also absorbs carbon dioxide and moisture from the air.