Question

Select the correct answer from the choices A, B, C, and D which are given. Write only the letter corresponding to the correct answer.

Which of the following is a chemical reaction?

• A. Freezing of liquid mercury
• B. Dropping a sliced orange into a vat of sodium hydroxide.
• C. Adding yellow to blue to make green.
• D. Cutting a piece of paper into two pieces.

Answer 1

The correct option is B

Dropping a sliced orange into a vat of sodium hydroxide.

Explanation for correct option:

Option B

Chemical reaction:

• Chemical reactions are the phenomena that involve reactions between one or more reactants that undergo chemicals associated with absorption or liberation of energy leading to the formation of one or more new substances.
• When mango sliced dropped into sodium hydroxide, the chemical reaction occurs between acid and base.
• As mango contains citric acid and sodium hydroxide is the base when the reaction occurs between these two then water and salt form.
• New substances are formed during this reaction.

Reaction:

${\mathrm{C}}_6{\mathrm{H}}_8{\mathrm{O}}_7+3\mathrm{NaOH}\to 3{\mathrm{H}}_2\mathrm{O}+{\mathrm{Na}}_3{\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{O}}_7$

Therefore, option B is correct.

Explanation for incorrect options:

• During freezing of liquid mercury, adding yellow to blue to make green, cutting a piece of paper into two pieces no new substances are formed.

Therefore, options A, C, and D are incorrect.