Question

Metal M is a major constituent of steel. On reaction with dilute hydrochloric acid, M releases a gas G which burns with a pop sound along with the formation of a greenish coloured solution C.

(i) Identify ‘M’ and ‘G’ from the following:

• A. M: Iron, G: Hydrogen gas
• B. M: Iron, G: Carbon dioxide gas
• C. M: Magnesium, G: Hydrogen gas
• D. M: Magnesium, G: Carbon dioxide gas

Answer 1

The correct option is A M: Iron, G: Hydrogen gas

Steel, an alloy, has iron as its major constituent. Therefore metal 'M' will be iron (Fe).

Iron reacts with dilute hydrochloric acid and results in the evolution of hydrogen gas which burns with a pop sound. Hence, gas 'G' will be hydrogen gas (${\text{H}}_2$).

$\text{Fe}\left(s\right)+\text{dil.2HCl}\left(aq\right)\to {\text{FeCl}}_2\left(aq\right)+{\text{H}}_2\left(g\right)$