Question

The weight percent of source (formula weight = 342 $gmo{l}^{-1}$ ) in an aqueous solution is 3.42. The density of the solution is 1 $gm{L}^{-1}$ , the concentration of sucrose in the solution in $mol{L}^{-1}$ is:

• A. 0.01
• B. 0.1
• C. 1
• D. 10

Answer 1

The correct option is B 0.1

The density of the solution is $1$ g /mL.
The mass of 1 L (1000 mL) of solution is $1000mL\times 1g/mL=1000g$

The weight per cent of sucrose in an aqueous solution is 3.42.

1000 g of aqueous solution contains $1000g\times \frac{3.42}{100}=34.2$ g.

The formula weight of sucrose is 342 g /mol.

The number of moles of sucrose $=\frac{34.2g}{342g}=0.1$ mole.

The concentration of sucrose solution is $\frac{0.1mol}{1L}=0.1M$

Hence, option B is correct.