Question

Four reactions are shown below in the diagram:

1.	2.
3.	4.

Which reactions produce water?

विकल्प

• 1 and 2

• 1 and 3

• 3 and 4

• 2 and 3

Answer 1

3 and 4

Explanation:

Reaction 3 shows the burning of ethanol, which is an example of combustion and combustion produces water and carbon dioxide.

\[\ce{C2H5OH + 3O2 -> 2CO2 + 3H2O}\]

Reaction 4 has dilute sulphuric acid and magnesium carbonate; a reaction of acid and carbonate produces salt, water and carbon dioxide.

\[\ce{MgCO3 + H2SO4 -> MgSO4 + CO2 + H2O}\]

Hence, reactions 3 and 4 produce water.