Question

How many moles of urea is present in \(250\) ml of \(0.2\,M\) solution of it?

• A. \(0.03\)
• B. \(0.04\)
• C. \(0.05\)
• D. \(0.06\)

Hint:

For molarity questions, always convert volume from ml to litre before applying \(n=MV\).

Answer 1

The Correct Option is C

Step 1: Molarity is defined as: \[ M=\frac{\text{Number of moles of solute}}{\text{Volume of solution in litres}} \]

Step 2: Therefore, \[ \text{Number of moles}=M \times V \]

Step 3: Given: \[ M=0.2\,M \] and \[ V=250\,ml=\frac{250}{1000}=0.25\,L \]

Step 4: Substitute the values: \[ \text{Moles}=0.2 \times 0.25 \] \[ =0.05 \]

Step 5: Hence, the number of moles of urea present is: \[ \boxed{0.05} \]