Import Question JSON

Current Question (ID: 18832)

Question:

$\text{Which of the following statements is false?}$

Options:

1. $\text{On passing H}_2\text{S through acidified K}_2\text{Cr}_2\text{O}_7 \text{ solution, a milky colour is observed.}$
2. $\text{Na}_2\text{Cr}_2\text{O}_7 \text{ is preferred over K}_2\text{Cr}_2\text{O}_7 \text{ in volumetric analysis.}$
3. $\text{K}_2\text{Cr}_2\text{O}_7 \text{ solution in an acidic medium is orange.}$
4. $\text{K}_2\text{Cr}_2\text{O}_7 \text{ solution becomes yellow in increasing the pH beyond 7}$

Solution:

$\text{HINT: K}_2 \text{Cr}_2 \text{O}_7 \text{ solution in acidic medium is orange.}$ $\text{Explanation:}$ $1. \text{On passing H}_2\text{S through acidified K}_2 \text{Cr}_2 \text{O}_7 \text{ solution, a milky colour is observed (because of S).}$ $\text{The reaction is: } K_2 \text{Cr}_2 \text{O}_7 + 4\text{H}_2\text{SO}_4 + 3\text{H}_2\text{S} \rightarrow K_2\text{SO}_4 + \text{Cr}_2(\text{SO}_4)_3 + 7\text{H}_2\text{O} + 3\text{S}$ $2. \text{Sodium dichromate, Na}_2 \text{Cr}_2 \text{O}_7 \text{ is hygroscopic in nature. Therefore, it cannot be used in volumetric analysis.}$ $3. \text{When KOH solution is added to potassium dichromate, the color of the solution becomes yellow because dichromate ions react with KOH and convert into chromate ions, which have yellow color.}$ $\text{Reactions involved are:}$ $2\text{CrO}_4^{2-} + 2\text{H}^+ \rightarrow \text{Cr}_2\text{O}_7^{2-} + \text{H}_2\text{O}$ $\text{Cr}_2\text{O}_7^{2-} + 2\text{OH}^- \rightarrow 2\text{CrO}_4^{2-} + \text{H}_2\text{O}$

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
}