Import Question JSON

Current Question (ID: 18074)

Question:

$\text{The relative lowering of vapour caused by dissolving 71.3 g of a substance in 1000 g of water is } 7.13 \times 10^{-3}. \text{ The molecular mass of the substance is-}$

Options:

1. $180 \text{ g mol}^{-1}$
2. $18 \text{ g mol}^{-1}$
3. $1.8 \text{ g mol}^{-1}$
4. $360 \text{ g mol}^{-1}$

Solution:

$\text{Hint: } \frac{\Delta P}{P} = \frac{n_A}{n_A + N}$ $\text{Step 1:}$ $\text{The formula of relative lowering in vapour pressure is-}$ $\frac{\Delta P}{P} = \frac{n_A}{n_A + N}$ $\text{Step 2:}$ $\text{Calculate the value of molar mass as follows:}$ $7.13 \times 10^{-3} = \frac{\frac{71.3}{m}}{\frac{71.3}{m} + N}$ $7.13 \times 10^{-3} = \frac{a}{a + 55.5}$ $0.0071 \times (a + 55.5) = a$ $0.4 + 0.0071a = a$ $0.4 = 0.992a$ $0.4 = 0.992 \times \frac{71.3}{m}$ $m = \frac{0.992 \times 71.3}{0.4}$ $= 180$

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
}