Import Question JSON

Current Question (ID: 18045)

Question:

$\text{If the density of lake water is } 1.25 \text{ g mL}^{-1} \text{ and contains } 92 \text{ g of Na}^+ \text{ ions per kg of water, then the molality of Na}^+ \text{ ions will be:}$

Options:

1. $3.24 \text{ molal}$
2. $4 \text{ molal}$
3. $5 \text{ molal}$
4. $3.5 \text{ molal}$

Solution:

$\text{Number of moles of Na}^+ \text{ ions} = \frac{92 \text{ g}}{23 \text{ g}} \text{ mol}^{-1} = 4 \text{ mol}$ $\text{So, Molality of Na}^+ \text{ ions in the lake} = \frac{\text{Number of moles of Na}^+ \text{ ions}}{\text{mass of water (in Kg)}} = \frac{4 \text{ mol}}{1 \text{ Kg}} = 4 \text{ molal}$

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
}