Question

When the same amount of zinc is treated separately with an excess dilute sulphuric acid and excess sodium hydroxide, the ratio of volumes of hydrogen evolved is ______.  

Options

• 1 : 1

• 1 : 2

• 2 : 1

• 9 : 4

Answer 1

When the same amount of zinc is treated separately with an excess dilute sulphuric acid and excess sodium hydroxide, the ratio of volumes of hydrogen evolved is 1 : 1.

Explanation:

\[\ce{Zn + \underset{(Excess)}{H2SO4} → ZnSO4 + H2 ↑}\]

\[\ce{Zn + \underset{Excess)}{2NaOH} → \underset{Sodium zincate}{Na2ZnO2 + H2 ↑}}\] 

∴ Ratio of volumes of H₂ evolved is 1 : 1.