Question

Assertion: Chemical combinations always take place between two elements.

Reason: A single substance is formed in a combination reaction.

• A. If both assertion and reason are true and the reason is the correct explanation of assertion.
• B. If both assertion and reason are true but the reason is not the correct explanation of assertion.
• C. If the assertion is true but the reason is incorrect.
• D. If the assertion is incorrect but the reason is correct.

Answer 1

The correct option is D

If the assertion is incorrect but the reason is correct.

The explanation for the correct option.

(D) If the assertion is incorrect but the reason is correct.

The explanation for the assertion.

1. Chemical combinations can take place between elements, molecules, and compounds, or all of them.
2. Example - Molecules of nitrogen gas$\mathbf{\left(}{\mathbf{N}}_{\mathbf{2}}\mathbf{\right)}$ and oxygen gas$\mathbf{\left(}{\mathbf{O}}_{\mathbf{2}}\mathbf{\right)}$ combine with water$\mathbf{\left(}{\mathbf{H}}_{\mathbf{2}}\mathbf{O}\mathbf{\right)}$ to form ammonium nitrate$\mathbf{\left(}{\mathbf{NH}}_{\mathbf{4}}{\mathbf{NO}}_{\mathbf{3}}\mathbf{\right)}$.

$2{\mathrm{N}}_2\left(\mathrm{g}\right)+4{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\to 2{\mathrm{NH}}_4{\mathrm{NO}}_3\left(\mathrm{s}\right)$

Hence, the assertion is incorrect.

The explanation for the reason statement.

Combination reaction

1. Combination reactions involve the combination of two or more elements, molecules, or compounds.
2. Only a single substance is formed by the combination of all the reactants.

Hence, the reason is correct.

Therefore, the correct option is (D).