Question

Which of the following reaction will not produce dihydrogen(H2)? Zn + NaOH O Zn + H2SO4 (dilute) Zn + H2SO4 (conc.) Coke + H20 (steam)​

Answer 1

Answer:

option c

Explanation:

zinc on reaction with concentrated sulphuric acid does not liberate hydrogen gas as the produced h2 get oxidised to water.

Answer 2

Among the following, the reaction that will not produce dihydrogen is $\[Zn + {H_2}S{O_4}\,(conc.)\]$.

Explanation:

• The reaction of zinc with sodium hydroxide produces sodium zincate and dihydrogen.

        $\[Zn + 2NaOH \to N{a_2}Zn{O_2} + {H_2}\]$

• Zinc reacts with dilute sulphuric acid to form zinc sulphate and dihydrogen.

        $\[Zn + {H_2}S{O_4} \to ZnS{O_4} + {H_2}\]$

• Zinc reacts with concentrated sulphuric acid to form zinc sulphate, water and sulphur dioxide.

        $\[Zn + 2{H_2}S{O_4} \to ZnS{O_4} + 2{H_2}O + S{O_2}\]$

• The reaction of coke and water (steam) gives water gas ($\[CO + {H_2}\]$).

        $\[C + {H_2}O \rightleftharpoons CO + {H_2}\]$

• Thus, the reaction of zinc with concentrated sulphuric acid does not produce dihydrogen.