Question

The substance that takes part in a chemical reaction is known as

• A. Reactant
• B. Product
• C. Equation
• D. Both A and B

Answer 1

The correct option is A

Reactant

The explanation for the correct answer

Option A

• A chemical reaction is a process in which substance(s) undergoes a chemical change to produce a new substance(s) having different properties.
• Substance(s) that take part in a chemical reaction is known as the reactant(s).
• Example: Combination of $\mathrm{Hydrogen}\left({\mathrm{H}}_2\right)$and $\mathrm{Oxygen}\left({\mathrm{O}}_2\right)$ to form $\mathrm{Water}$$\left({\mathrm{H}}_2\mathrm{O}\right)$ is a chemical reaction. Here $\mathrm{Hydrogen}\left({\mathrm{H}}_2\right)$ and $\mathrm{Oxygen}\left({\mathrm{O}}_2\right)$ are reactant while $\mathrm{Water}$ is the product.
• Chemical equation: $\underset{\mathrm{Reactant}1}{2{\mathrm{H}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Reactant}2}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Product}}{2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)}$

The explanation for the incorrect answer

Option B

• A chemical reactions occur when two or more substances combine to form a new substance.
• New substance formed in a chemical reaction is known as a product.
• Example: Combination of $\mathrm{Nitrogen}\left({\mathrm{N}}_2\right)$and $\mathrm{Hydrogen}\left({\mathrm{H}}_2\right)$ to form $\mathrm{Ammonia}\left({\mathrm{NH}}_3\right)$ is a chemical reaction. Here $\mathrm{Nitrogen}$ and $\mathrm{Oxygen}$ are reactants while $\mathrm{Ammonia}$ is the product.
• Chemical equation:$\underset{Nitrogen}{{\mathrm{N}}_2(\mathrm{g}})+\underset{\mathrm{Hydrogen}}{3{\mathrm{H}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Ammonia}}{2{\mathrm{NH}}_3\left(\mathrm{g}\right)}$.

Option C

• Chemical equation is a method of representing chemical reaction in terms of symbols and formulae of substances.
• Reactants are always written on the left-hand side of the equation and products are written on the right-hand side of the equation.
• Example: when an electric current is passed through molten$\mathrm{Sodium}\mathrm{chloride}\left(\mathrm{NaCl}\right)$, it decomposes to give $\mathrm{Sodium}\left(\mathrm{Na}\right)$ metal and $\mathrm{Chlorine}\left({\mathrm{Cl}}_2\right)$ gas. Here $\mathrm{Sodium}\mathrm{chloride}$ is the reactant and$\mathrm{Sodium}\left(\mathrm{Na}\right)$,$\mathrm{Chlorine}\left({\mathrm{Cl}}_2\right)$ are the products.
• Chemical equation: $\underset{\mathrm{Sodium}\mathrm{chloride}}{2\mathrm{NaCl}\left(\mathrm{s}\right)}\stackrel{\mathrm{electricity}}{\to }\underset{\mathrm{Sodium}}{2\mathrm{Na}\left(\mathrm{l}\right)}+\underset{\mathrm{Chlorine}}{{\mathrm{Cl}}_2(\mathrm{l}})$

Thus Option A i.e., Reactant is the correct answer.