Question

Assertion :Both $H_{3}P{O}_2$ and $H_{3}P{O}_3$ have $31$ grams of phosphorus in their one mole compound. Reason: Oxygen has the highest mass percentage in both the compounds.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

Both $H_{3}P{O}_2$ and $H_{3}P{O}_3$ have $1atom$ of phosphorous $\left(P\right)$ per molecule. Mass of 1 mole atom is equal to molar mass of atom which is $31g$ for phosphorous.

Molecular weight of $H_{3}P{O}_2=66$

Mass percent of oxygen is $=\frac{32}{66}\times 100=48.4\%$

Mass percent of phosphorous is $=\frac{31}{66}\times 100=46.5\%$

Molecular weight of $H_{3}P{O}_3=82$

Mass percent of oxygen is $=\frac{48}{82}\times 100=58.5\%$

Mass percent of phosphorous is $=\frac{31}{82}\times 100=37.8\%$

Oxygen has the highest mass percentage in both the compounds.

Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion