Question

Name the gas which is liberated when an acid reacts with a metal? How will
you test the presence of this gas?
Write the chemical equation for the reaction of zinc metal with
(a) hydrochloric acid and (b) with sodium hydroxide. Write the chemical name
of salt obtained in each case.
Identify the acid and base for ammonium chloride salt. What would be the
nature of this salt? Mention the pH range of this salt.
(iii)​

Answer 1

Hydrogen gas is usually liberated when an acid reacts with a metal.

Take few pieces of zinc granules and add 5 ml of dilute \( \mathrm { H } _ { 2 } \mathrm { SO } _ { 4 } \). Shake it and pass the gas produced into a soap solution. The bubbles of the soap solution are formed. These soap bubbles contain hydrogen gas.

\( 2 \mathrm { H } _ { 2 } \mathrm { SO } _ { 4 } + \mathrm { Zn } \longrightarrow \mathrm { Zn } \left( \mathrm { SO } _ { 4 } \right) _ { 2 } + 2 \mathrm { H } _ { 2 } \uparrow\)

we can test the evolved hydrogen gas by its burning with a pop sound when a candle is brought near the soap bubbles

Answer 2

hydrogen gas is liberated when acid reacts with a metal

HCL +ZN = ZNCL +H2

ZN +NAOH = 2NAOHNA2ZNO2