Question

A boy drinks 500 mL of 9% glucose solution. The number of glucose molecules he has consumed is:

• A. $0.5\times {10}^{23}$
  
• B. $1.0\times {10}^{23}$
• C. $1.5\times {10}^{23}$
• D. $2.0\times {10}^{23}$

Answer 1

Answer: (C)

$1.5\times {10}^{23}$

The correct option is (c)

Explanation:

9 % w/v means 9 grams glucose per 100 ml of solution.

$\frac{9g}{100}ml\times 500$ ml=45 g glucose in the 500 ml solution

molar mass of glucose = 180g/mole

mole of glucose consumed=$\frac{45g\times 1mole}{180g}$=$0.25$moles of glucose consumed

molecules of glucose=$0.25moles\times 6.02\times {10}^{23}$ molecules/mole

=$1.5\times {10}^{23}$ molecules consumed