Import Question JSON

Current Question (ID: 8507)

Question:

$\text{In a buffer solution containing an equal concentration of B}^- \text{ and HB, the } K_b \text{ for B}^- \text{ is } 10^{-10}\text{. pH of the buffer solution is:}$

Options:

1. $10$
2. $7$
3. $6$
4. $4$

Solution:

$\text{Hint: } \text{pOH} = \text{pK}_b + \log \frac{[\text{salt}]}{[\text{base}]}$ $\text{Step 1:}$ $\text{Calculate the value of pOH as follows:}$ $\text{(i) For basic buffer}$ $\text{pOH} = \text{pK}_b + \log \frac{[\text{salt}]}{[\text{base}]}$ $\text{(ii) pH + pOH = 14}$ $\text{Given, } K_b = 1 \times 10^{-10}, [\text{salt}] = [\text{base}]$ $\text{pOH} = -\log K_b + \log \frac{[\text{salt}]}{[\text{base}]}$ $\text{pOH} = -\log(1 \times 10^{-10}) + \log 1$ $\text{pOH} = 10 + 0 = 10$ $\text{Step 2:}$ $\text{Calculate the value of pH is as follows:}$ $\text{pH + pOH = 14}$ $\text{pH} = 14 - 10 = 4$ $\text{Hence, the pH of buffer solution is 4.}$

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
}