Question

Calculate the molarity of a solution having 3.42 g sucrose in 500 mL solution.

• A. 0.2 M
• B. 0.02 M
• C. 2 M
• D. 0.342 M

Answer 1

The correct option is B

0.02 M

We know that,
$Molarity=\frac{Numberofmolesofsolute}{Numberoflitresofsolution}$

We know the given weight of sucrose from which the number of moles of sucrose can be calculated.

Therefore $Numberofmoles=\frac{givenweight}{Molecularweight}$
$=\frac{3.42}{342}=0.01$

When 0.01 moles of sucrose is added to 500 mL

$\Rightarrow Molarity=0.01\times \frac{1}{500\times {10}^{-3}}(1mL={10}^{-3}L)$

$\Rightarrow Molarity=0.02M$