Import Question JSON

Current Question (ID: 8473)

Question:

$0.561 \text{ g of } \text{KOH} \text{ is dissolved in water to give } 200 \text{ mL of solution at } 298 \text{ K}. \text{ The pH of the solution will be}$

Options:

1. $12.70$
2. $1.30$
3. $3.14$
4. $11.70$

Solution:

$\textbf{Hint: } \text{pH} = -\log[\text{H}^+]$ $\textbf{Step 1: } \text{Calculate the hydroxide ion concentration}$ $0.561 \text{ g of } \text{KOH} \text{ is dissolved in water to give } 200 \text{ mL of solution}$ $\text{So, Concentration of } \text{KOH} = \frac{0.561}{56.1} \times \frac{1000}{200} = 0.05 \text{ M}$ $\text{KOH}_{(\text{aq})} \rightarrow \text{K}^+_{(\text{aq})} + \text{OH}^-_{(\text{aq})}$ $[\text{OH}^-] = [\text{KOH}] = 0.05 \text{ M}$ $\textbf{Step 2: } \text{Calculate pH}$ $\text{We know that, } K_w = [\text{H}^+][\text{OH}^-]$ $\Rightarrow [\text{H}^+] = \frac{10^{-14}}{0.05} = 2 \times 10^{-13}$ $\text{Thus, pH} = -\log(2 \times 10^{-13}) = 12.70$

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
}