Q8 / 180 · KCET 2015 · Chemistry
On heating with concentrated \( \mathrm{NaOH} \) solution in an inert atmosphere of \( \mathrm{CO}_{2} \), white
phosphorous gives a gas. Which of the following statement is incorrect about the gas?
phosphorous gives a gas. Which of the following statement is incorrect about the gas?
- AIt is less basic than \( \mathrm{NH}_{3} \)
- Correct answerBIt is more basic than \( \mathrm{NH}_{3} \).
- CIt is highly poisonous and has smell like rotten fish.
- DIt's solution in water decomposes in the presence of light.
Solution
\( \mathrm{P}_{4}+3 \mathrm{NaOH}+3 \mathrm{H}_{2} \mathrm{O}-\stackrel{\Delta}{\mathrm{CO}_{2}}>3 \mathrm{~N} a \mathrm{H}_{2} \mathrm{PO}_{2}+\mathrm{PH}_{3} \uparrow \) (phosphine)
\( \mathrm{PH}_{3} \) is less basic than \( \mathrm{NH}_{3} \) because lone pairs of electrons are less available in \( \mathrm{PH}_{3} \) and \( \mathrm{NH}_{3} \) due to larger size of
the phosphorous than nitrogen.
\( \mathrm{PH}_{3} \) is less basic than \( \mathrm{NH}_{3} \) because lone pairs of electrons are less available in \( \mathrm{PH}_{3} \) and \( \mathrm{NH}_{3} \) due to larger size of
the phosphorous than nitrogen.
Hence, the correct answer is option: 'B'.