Question

The metal which produces hydrogen gas on reaction with dilute hydrochloric acid as well as sodium hydroxide solution is:
A.Copper
B.Iron
C.Aluminum
D.Sodium

Answer 1

Hint:
 Amphoteric oxides are oxides which react both as an acid and as a base. Many metals such as copper, zinc, aluminum, tin, lead and beryllium form amphoteric oxides or hydroxides.

Complete step by step answer:
Sodium is a very reactive metal, so it reacts violently even with cold water.
Aluminium reacts with hydrochloric acid as well as sodium hydroxide solution to produce hydrogen gas.
Further, the equation is,
\[2Al\left( s \right) + 6HCl\left( {aq} \right) \to 3{H_2}\left( g \right) + 2AlC{l_3}(aq)\] $2Al\left( s \right) + 2NaOH\left( {aq} \right) + 2{H_2}\;O\left( l \right) \to \;2N{\text{aAl}}{{\text{O}}_2} + 3H$
Aluminium oxide is amphoteric. It has reactions as both a base and an acid. The oxide ions are held too strongly in the solid lattice to react with the water.
Aluminium oxide contains oxide ions, and thus reacts with acids in the same way sodium or magnesium oxides do.
It acts as an acid with the base, and a base with an acid, neutralizing the other and producing a salt.

Hence, option C is correct.

Additional information
-Aluminium is used in a huge variety of products including cans, foils, kitchen utensils, aeroplane parts.
-Aluminium metal rapidly develops a thin layer of aluminum oxide of a few millimeters that prevents the metal from reacting with water.
-When this layer is corroded a reaction develops, releasing highly flammable hydrogen gas.

Note:
Copper also reacts with dil HCl and produces hydrogen and it also reacts with NaOH.
The equations are as shown,
         \[Cu\left( s \right) + 2HCl(aq) \to CuCl{}_2\;(aq) + {H_{2(g)}}\]
          \[Cu(s) + 2NaOH(aq) \to Cu{}_2{\left( {OH} \right)_{2\;\;}} + 2Na(s)\]