Question

You are provided with two containers made up of copper and aluminium. You are also provided with solutions of dilute $HCl$, dilute $HN{O}_3,ZnC{l}_2$ and $H_{2}O$ respectively. In which of the above containers these solutions can be kept respectively?

• A. Copper, Aluminium, Copper, Copper
  
• B. Copper, Aluminium, Aluminium, Copper
  
• C. Aluminium, Copper, Copper, Aluminium
  
• D. Aluminium, Aluminium, Copper, Copper
  

Answer 1

The correct option is A Copper, Aluminium, Copper, Copper

A) Reactivity of copper in different solutions:
i) Dilute HCl:
Copper does not react with dilute HCl, so latter can be stored in a copper vessel.

ii) Dilute $HN{O}_3$:
Dilute $HN{O}_3$ cannot be stored in copper vessel as following chemical reaction takes place:
$3Cu\left(s\right)+8HN{O}_3\left(aq\right)\to 3Cu\left(N{O}_3{)}_2\right(aq)+2NO(g)+4H_{2}O(l)$

III) $ZnC{l}_2$:
$ZnC{l}_2$ can be stored in copper vessel as no reaction takes place because copper is less active metal than zinc and can't displace it from $ZnC{l}_2$ solution.

iv) $H_{2}O$:
No reaction occurs between copper and water so water can be stored in copper vessel.

B) Reactivity of Aluminium with different solutions:
i) Dilute HCl:
Aluminium reacts with dilute HCl to form its salt, thus dilute HCl cannot be stored in aluminium vessel.
$2Al+6HCl\to 2AlC{l}_3+3H_2$

ii) Dilute $HN{O}_3$:
Aluminum reacts with nitric acid to form a passive layer of aluminium oxide($A{l}_2{O}_3$) which protects aluminium from further oxidation.Therefore dilute nitric acid can be stored in aluminium vessel.

iii) $ZnC{l}_2$:

Aluminium being more active metal than zinc displaces latter from its solution ,thus zinc chloride cannot be stored in aluminium vessel.
$2Al+3ZnC{l}_2\to 2AlC{l}_3+3Zn$

iv) $H_{2}O$:
Aluminium does not react with cold water and when attacked by steam also, it forms a protective aluminium oxide ($A{l}_2{O}_3$) layer which prevents further reaction.
$2Al\left(s\right)+3H_{2}O\left(l\right)\to A{l}_2{O}_3\left(s\right)+3H_2\left(g\right)$