A concentrated ution of copper sulphate, which is dark blue in colour, a mixed at room temperature with a dilute ution of copper sulphate, which is light blue. For this process-

• A

  Entropy change is positive, but enthalpy change is negative
• B

  Entropy and enthalpy changes are both positive
• Correct answer
  C

  Entropy change is positive and enthalpy does not change
• D

  Entropy change is negative and enthalpy change is positive

Hence, the correct answer is option: 'C'.