Chapter U4.15, Problem 7E

Interpretation Introduction

Interpretation:

Between a sucrose solution (20 g sucrose in 1 L) and a glucose solution (20 g glucose in 1 L) which is more concentrated must be explained.

Concept introduction:

Molecular weight of sucrose is 342 g/mol and that of glucose is 180 g/mol.

Answer to Problem 7E

20 g glucose in 1L solution is more concentrated as compared to 20 g sucrose in 1 L solution.

Explanation of Solution

Molarity of glucose in 1 L of the solution will be equal to the number of moles which can be calculated from its mass and molar mass as follows:

  $M_{\text{glucose}}=\frac{n}{1\text{ L}}=\frac{\text{mass}}{\text{molar mass}}=\frac{20}{180}=0.11\text{ M}$

Similarly,

  $M_{\text{sucrose}}=\frac{n}{1\text{ L}}=\frac{\text{mass}}{\text{molar mass}}=\frac{20}{342}=0.06\text{ M}$

Thus molarity of glucose solution is higher as compared to sucrose solution.

Conclusion

Glucose solution is more concentrated.