Import Question JSON

Current Question (ID: 8247)

Question:

$\text{The correct statement among the following is:}$

Options:

1. $\text{The presence of reacting species in a covered beaker is an example of an open system.}$
2. $\text{There is an exchange of energy as well as matter between the system and the surroundings in a closed system.}$
3. $\text{The presence of reactants in a closed vessel made up of copper is an example of a closed system.}$
4. $\text{The presence of reactants in a thermos flask or any other closed insulated vessel is an example of a closed system.}$

Solution:

$\textbf{Hint:} \text{In a closed system, only an exchange of energy is taking place}$\n\n$\text{For a closed vessel made of copper, no matter can exchange between the system and the surroundings but energy exchange can occur through its walls. Copper is a good conductor of heat. Thus, in a copper vessel, only heat can exchange but matter does not exchange.}$\n\n$\text{Let us analyze each option:}$\n\n$\bullet \, \text{Option 1: A covered beaker still allows matter exchange (gases can escape), so it's not completely closed - this is incorrect.}$\n\n$\bullet \, \text{Option 2: In a closed system, only energy can exchange, not matter - this statement is incorrect as it says both energy and matter exchange.}$\n\n$\bullet \, \text{Option 3: A closed copper vessel prevents matter exchange but allows energy (heat) exchange due to copper's thermal conductivity - this is a correct example of a closed system.}$\n\n$\bullet \, \text{Option 4: A thermos flask or insulated vessel prevents both energy and matter exchange - this would be an isolated system, not a closed system.}$\n\n$\text{Therefore, option (3) is correct.}$

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
}