Import Question JSON

Current Question (ID: 10565)

Question:

$\text{A solid (A) reacts with strong aqueous NaOH, liberating a foul smelling gas (B), which spontaneously burns in the air, giving smoky rings. A and B are, respectively:}$

Options:

1. $\text{P}_4\text{ (red) and PH}_3$
2. $\text{P}_4\text{ (white) and PH}_3$ (Correct)
3. $\text{S}_8\text{ and H}_2\text{S}$
4. $\text{P}_4\text{ (white) and H}_2\text{S}$

Solution:

$\text{Hint: PH}_3\text{ burn in air to give smoky rings.}$ $\text{Explanation:}$ $\text{STEP 1: White phosphorous (A) reacts with strong aqueous NaOH liberating a foul smelling gas PH}_3\text{ (B) which spontaneously burn in air giving smoky rings of P}_4\text{O}_{10}$ $\text{STEP 2: The reaction can be given as:}$ $\text{P}_4\text{(s)} + 3\text{NaOH(aq)} + 3\text{H}_2\text{O(l)} \rightarrow \text{PH}_3\text{(g)} + 3\text{NaH}_2\text{PO}_2\text{(aq)}$ $\text{Pure phosphine is odourless, but technical grade samples have a highly unpleasant odour like rotting fish, due to the presence of substituted phosphine and diphosphane.}$ $\text{STEP 3:}$ $\text{Phosphine burn in air to give P}_4\text{O}_{10}\text{ which acts as smoke screens.}$ $4\text{PH}_3 + 8\text{O}_2 \xrightarrow{\Delta} \text{P}_4\text{O}_{10} + 6\text{H}_2\text{O}$

Import JSON File

Upload a JSON file containing LaTeX/MathJax formatted question, options, and solution.

Expected JSON Format:

{
  "question": "The mass of carbon present in 0.5 mole of $\\mathrm{K}_4[\\mathrm{Fe(CN)}_6]$ is:",
  "options": [
    {
      "id": 1,
      "text": "1.8 g"
    },
    {
      "id": 2,
      "text": "18 g"
    },
    {
      "id": 3,
      "text": "3.6 g"
    },
    {
      "id": 4,
      "text": "36 g"
    }
  ],
  "solution": "\\begin{align}\n&\\text{Hint: Mole concept}\\\\\n&1 \\text{ mole of } \\mathrm{K}_4[\\mathrm{Fe(CN)}_6] = 6 \\text{ moles of carbon atom}\\\\\n&0.5 \\text{ mole of } \\mathrm{K}_4[\\mathrm{Fe(CN)}_6] = 6 \\times 0.5 \\text{ mol} = 3 \\text{ mol}\\\\\n&1 \\text{ mol of carbon} = 12 \\text{ g}\\\\\n&3 \\text{ mol carbon} = 12 \\times 3 = 36 \\text{ g}\\\\\n&\\text{Hence, 36 g mass of carbon present in 0.5 mole of } \\mathrm{K}_4[\\mathrm{Fe(CN)}_6].\n\\end{align}",
  "correct_answer": 4
}