Question

Which of the following pairs will give displacement reactions?

• A. $NaCl$ solution and copper metal
• B. $MgCl_2$ solution and aluminium metal
• C. $FeSO_4$ solution and silver metal
• D. $AgNO_3$ solution and copper metal

Answer 1

Answer: (D)

$AgNO_3$ solution and copper metal

Answer 2

In accordance with the electrochemical series, a metal positioned higher in the series displaces another metal from its salt if the latter metal is lower in the series.
Considering the electrochemical series:

• Sodium (Na) is positioned above copper (Cu), indicating that a displacement reaction is not possible.
• Magnesium (Mg) is situated above aluminum (Al), suggesting that a displacement reaction is not possible.
• Iron (Fe) is higher in the series than silver (Ag), implying that a displacement reaction is not possible.

However, a displacement reaction occurs between copper metal and silver nitrate solution because copper (Cu) is higher in the series than silver (Ag). The corresponding chemical equation can be expressed as:

$Cu+2AgNO_3→Cu(NO_3)_2+2Ag$