Same chapter3 marksDifficulty: Medium
State three uses of hydrogen.
Study of the First Element: Hydrogen
3 marksDifficulty: Medium
Write the equation for the laboratory preparation of hydrogen and state why granulated zinc and dilute sulphuric acid are used.
Original Khojo Papers practice question — not from a past board paper.
Answer
Zn + H2SO4 (dilute) → ZnSO4 + H2. Granulated zinc is used because pure zinc reacts too slowly and the impurities in granulated zinc speed the reaction; dilute sulphuric acid is used because concentrated sulphuric acid would oxidise the hydrogen and dilute nitric acid is an oxidising agent that gives oxides of nitrogen instead.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
A little copper sulphate solution is sometimes added to speed the reaction further.
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