Question

Match the following:

• A. P-III, Q-I, R-II, S-IV
• B. P-II, Q-IV, R-I, S-III
• C. P-II, Q-IV, R-III, S-I
• D. P-II, Q-I, R-IV, S-III

Answer 1

The Correct Option is B

We are given the mass of different molecules and are asked to match it with the number of molecules. We can use the formula:
\[ \text{Number of molecules} = \frac{\text{Mass of substance}}{\text{Molar mass of substance}} \times N_A \] Where \( N_A \) is Avogadro's number. Using the molar masses:
- Molar mass of \( H_2O \) = 18 g/mol
- Molar mass of Carbon = 12 g/mol
- Molar mass of \( H_2SO_4 \) = 98 g/mol
- Molar mass of NaCl = 58.5 g/mol
We calculate the number of molecules for each compound:
Step 1: For H₂O (P)
\[ \text{Number of molecules of } H_2O = \frac{3.6}{18} \times N_A = 0.2 \times N_A = 0.5 \times 10^4 N_A \] So, \( P \) matches with \( I \).
Step 2: For Carbon (Q)
\[ \text{Number of molecules of Carbon} = \frac{1.8}{12} \times N_A = 0.15 \times N_A = 2 \times 10^4 N_A \] So, \( Q \) matches with \( IV \).
Step 3: For H₂SO₄ (R)
\[ \text{Number of molecules of } H_2SO_4 = \frac{4.9}{98} \times N_A = 0.05 \times N_A = 1 \times 10^4 N_A \] So, \( R \) matches with \( I \).
Step 4: For NaCl (S)
\[ \text{Number of molecules of NaCl} = \frac{5.85}{58.5} \times N_A = 0.1 \times N_A = 1.5 \times 10^4 N_A \] So, \( S \) matches with \( III \). Thus, the correct match is: P-II, Q-IV, R-I, S-III. Final Answer: P-II, Q-IV, R-I, S-III