Practicing Success

Target Exam

CUET

Subject

Chemistry

Chapter

Physical: Solutions

Question:

What is the mole fraction of 90 g of glucose (C6H12O6) dissolved in 900 g of water (H2O)?

Options:

0.006

0.007

0.008

0.009

Correct Answer:

0.009

Explanation:

Molar mass of C6H12O6 = 12 × 6 + 1 × 12 + 16 × 6 = 180 g mol–1 .

Moles of C6H12O6  = \(\frac{90}{180}\) = 0.5 mol

Moles of H2O = \(\frac{900}{18}\) = 50 mol

mole fraction of C6H12O6 = \(\frac{\text{moles of  } C_6H_{12}O_6 }{\text{moles of} C_6H_{12}O_6 +\text{ moles of }H_2O }\)

mole fraction of C6H12O6 = \(\frac{0.5}{0.5+50}\)

mole fraction of C6H12O6 = \(\frac{0.5}{50.5}\)

mole fraction of C6H12O6 = 0.009