Question

A student was given mg,zn,fe,and cu metals. he put each of them in dil hcl contained in different test tubes. identify which of them
1.will not displace h2 from dil hcl
2.forms a pale green substance
3.will give h2 with 5%hno3
4.will be displaced from its salt solution by all other metals.

Answer 1

Hey there !

Solution:

Given Metals: Magnesium, Zinc, Iron and Copper

1 ) Copper is the element which will not displace Hydrogen from Hydrochloric acid. This is because in the reactivity series Copper is less reactive due to which it cannot displace Hydrogen which is more reactive.

2 ) Iron on reacting with Hydrochloric acid provides a green colored pale substance as the iron displaces Hydrogen from it's salt thus forming Iron chloride and Hydrogen gas.

3 ) Magnesium and Manganese are the only elements which react with Nitric acid to give Hydrogen gas. Since nitric acid is a strong oxidizing agent, it will give only oxides after reaction. But magnesium and Manganese alone give hydrogen on reaction.

4 ) Copper is the only element in the given series in which it will be displaced from it's salt solution by all other elements. This is because according to reactivity series, Copper is the least reactive among these elements due to which they get displaced.

Hope my answer helped !