Question

0.05M CuSO$_4$ when treated with 0.01M K$_2$Cr$_2$O$_7$ gives green colour solution of Cu$_2$Cr$_2$O$_7$. The $\text{[SPM : Semi Permeable Membrane]}$$K_2Cr_2O_7$	$CuSO_4$
Side X	SPM

Due to osmosis:

• A. Green colour formation observed on side Y.
• B. Green colour formation observed on side X.
• C. Molarity of$K_2Cr_2O_7$solution is lowered.
• D. Molarity of$CuSO_4$solution is lowered.

Answer 1

Answer: (D)

Molarity of$CuSO_4$solution is lowered.

Answer 2

Due to osmosis, the solvent molecules from side Y (CuSO 4) diffuse across the semi-permeable membrane (SPM) into side X (K 2Cr2O7). This dilution effect causes the molarity of the CuSO 4 solution (side Y) to decrease over time.

• CuSO 4 reacts with K 2Cr2O7, forming Cu 2Cr2O7, which is responsible for the green color.
• The green color is observed due to the formation of Cu 2Cr2O7, but the key change is in the molarity of the CuSO 4 solution on side Y , which decreases as the solvent diffuses.

Thus the correct answer is Option 4.