Import Question JSON

Current Question (ID: 21015)

Question:

$\text{The average S--F bond energy in kJ mol}^{-1} \text{ of SF}_6 \text{ is:}$ $\text{[The values of standard enthalpy of formation of SF}_6\text{(g), S(g), and F(g) are } -1100, 275, \text{ and } 80 \text{ kJ mol}^{-1} \text{ respectively.]}$

Options:

1. $309 \text{ kJ mol}^{-1}$
2. $313 \text{ kJ mol}^{-1}$
3. $305 \text{ kJ mol}^{-1}$
4. $318 \text{ kJ mol}^{-1}$

Solution:

$\Delta H^\circ = \sum n \Delta H_f^\circ (\text{products}) - \sum n \Delta H_f^\circ (\text{reactants})$ $\text{Use the formula } \Delta_r H = 6 \epsilon_{\text{S--F}}$ $\Delta_r H = 6 \times \epsilon_{\text{S--F}} = \Delta_f H(\text{S, g}) + 6 \times \Delta_f H(\text{F, g}) - \Delta_f H(\text{SF}_6, \text{ g}) = 275 + 6 \times 80 - (-1100)$ $= 1855 \text{ kJ}$ $\epsilon_{\text{S--F}} = \frac{1855}{6} = 309.16 \text{ kJ/mol}$ $\text{Hence, the correct answer is } 309 \text{ kJ/mol}$

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
}