72. NCERT Exemplar XXXXIX

 

 

Dilute \(HCl\): With dilute \(HCl\), copper does reactdoes not react. As a result, dilute \(HCl\) may be kept in a copper container.

 

Dilute \(HNO_3\): When copper reacts with dilute \(HNO_3\), copper nitrate and nitrogen monoxide gas are formed.

 

\(3Cu\) + \(8HNO_3\) → \(3Cu(NO_2)_3\)\(3Cu(NO_3)_2\)\(2Cu(NO_2)_3\)\(2Cu(NO_3)_2\) + \(2NO\) + \(4H_2O\)

 

Therefore, dilute \(HNO_3\) cannot be kept in a copper container.

 

\(ZnCl_2\) solution: Copper does not displace zinc from \(ZnCl_2\) solution because it is non reactivemore activeless reactivemore reactive than \(Zn\).

 

Hence, \(ZnCl_2\) solution can be stored in a copper container.

 

\(H_2O\) Water: Copper and water do not react. As a result, water may be kept in a copper container.

 

A copper container can be used to store diluted \(HCl\), \(ZnCl_2\) solution, and \(H_2O\).

 

 

Dilute \(HCl\): When aluminium reacts with dilute \(HCl\), it forms aluminium chloride and hydrogen gas.

 

\(2Al\) + \(6HCl\) → \(2AlCl_3\) + \(3H_2\) \(3AlCl_3\) + \(3H_2\) \(2AlCl_3\) + \(3Cl_2\) \(2AlCl_6\) + \(3H_2\)

 

As a result, dilute HCl cannot be kept in an aluminium container.

 

Dilute \(HNO_3\): Aluminium forms aluminium oxide when it reacts with dilute \(HNO_3\). The aluminium oxide layer does not reactdoes react any further after it has formed. Hence, dilute \(HNO_3\) can be stored in an aluminium container.

 

\(ZnCl_2\) solution: \(ZnCl_2\) solution combines with \(Al\) and forms aluminium chloride and zinc \(Zn\) metal.

 

\(3ZnCl_2\) + \(2Al\) → \(2AlCl_3\) + \(3Zn\)\(3AlCl_4\) + \(3Zn\)\(2AlCl_3\) + \(2Zn\)\(3AlCl_3\) + \(2Zn\)

 

Therefore, \(ZnCl_2\) solution cannot be stored in aluminum container.

 

\(H_2O\) Water: Aluminum and water (cold as well as hot water) do not react.

 

Therefore, water can be stored in aluminium container.

 

Dilute \(HNO_3\) and \(H_2O\) can be stored in an aluminium container.