Question

Read the following statements and choose the correct option:
Statement 1: Burning of magnesium ribbon is an exothermic reaction.
Statement 2: Decomposition of potassium nitrate is an endothermic reaction.

• A. Statement 1 is correct and statement 2 is wrong.
• B. Statement 1 is wrong and statement 2 is correct.
• C. Both statements are correct.
• D. Both statements are wrong.

Answer 1

The correct option is C Both statements are correct.

Burning of magnesium ribbon is exothermic in nature as heat and light are produced during this reaction. The reaction occurs as follows:
$2\text{Mg (s)}+{\text{O}}_2\text{(g)}\to 2\text{MgO (s)}+\text{Heat}$

The decomposition of potassium nitrate is an endothermic reaction as heat is absorbed in this reaction. The reaction occurs as follows:
$2{\text{KNO}}_3\text{(s)}\stackrel{\text{Heat}}{\to }2{\text{KNO}}_2\text{(s)}+{\text{O}}_2\text{(g)}$