Question

: One molar aqueous solution has always higher concentration than one molal. : The molality of a solution depends upon the density of the solution whereas molarity does not.

• A. If both Assertion: and Reason: are true and the Reason: is the correct explanation of the Assertion
• B. If both Assertion: and Reason: are true but the Reason: is not the correct explanation of the Assertion
• C. If Assertion: is true but Reason: is false
• D. If both Assertion: and Reason: are false

Answer 1

Answer: (B)

If both Assertion: and Reason: are true but the Reason: is not the correct explanation of the Assertion

Answer 2

In one molar aqueous solution, one mole solute is present in $1000\, mL$ of solution while in case of one molal solution, one mole solute is present in $1\, kg$ of solvent. Thus, former one is more concentrated if solvent is water. Molality depends upon mass of solvent which in turn is calculated by finding mass of solution for which density is required while molarity depends upon volume of solution, thus density is not required to calculate it. Hence, both Assertion and Reason are correct.