Q. 9.69 - An Introduction to General, Organic, and Biological Chemistry

Question

Are the following solutions isotonic, hypotonic, or hypertonic compared with a red blood cell?

a. distilled ${\mathrm{H}}_2\mathrm{O}$

b. $1\% (\mathrm{m}/\mathrm{v}) \mathrm{glucose}$

c. $0.9 \% (\mathrm{m}/\mathrm{v}) \mathrm{NaCl}$

d. $15 \% (\mathrm{m}/\mathrm{v}) \mathrm{glucose}$

Step-by-Step Solution

Answer

a. The distilled ${\mathrm{H}}_2\mathrm{O}$ is a hypotonic solution.

b. $1\% \mathrm{glucose}$ is a hypotonic solution.

c. $0.9 \% (\mathrm{m}/\mathrm{v}) \mathrm{NaCl}$ is an isotonic solution.

d. $15\% (\mathrm{m}/\mathrm{v}) \mathrm{glucose}$ is a hypotonic solution.

Part (a) Step 1: Given Information

We need to find whether distilled ${\mathrm{H}}_2\mathrm{O}$is isotonic, hypotonic, or hypertonic compared with a red blood cell.

Part (a) Step 2: Explanation

Distilled water is a pure solvent since it contains no solute particles. This means it has a lower concentration compared to isotonic solutions such as $0.9 (\mathrm{m}/\mathrm{v}) \mathrm{NaCl}$solution and $5\% (\mathrm{m}/\mathrm{v})$ solution, so it is called a hypotonic solution.

Part (b) Step 1: Given Information

We need to find whether $1\% (\mathrm{m}/\mathrm{v}) \mathrm{glucose}$ is isotonic, hypotonic, or hypertonic compared with a red blood cell. 

Part (b) Step 2: Explanation

A $1\% (\mathrm{m}/\mathrm{v})$ glucose solution has a lower concentration compared to the isotonic solution$5\% (\mathrm{m}/\mathrm{v})$ glucose solution, so it is a hypotonic solution.

Part (c) Step 1: Given Information

We need to find whether $0.9 \% (\mathrm{m}/\mathrm{v}) \mathrm{NaCl}$ is isotonic, hypotonic, or hypertonic compared with a red blood cell. 

Part (c) Step 2: Explanation

A $0.9\% (\mathrm{m}/\mathrm{v}) \mathrm{NaC}$l solution has the same concentration compared to the the isotonic $\mathrm{NaCl}$ solution $0.9 \% (\mathrm{m}/\mathrm{v}) \mathrm{NaCl}$ solution, so it is an isotonic solution.

Part (d) Step 1: Given Information

We need to find whether $15 \% (\mathrm{m}/\mathrm{v}) \mathrm{glucose}$ is isotonic, hypotonic, or hypertonic compared with a red blood cell. 

Part (d) Step 2: Explanation

A $15 \% (\mathrm{m}/\mathrm{v}) \mathrm{glucose}$ solution has a higher concentration compared to the isotonic glucose solution $15\% (\mathrm{m}/\mathrm{v}) \mathrm{glucose}$ solution, so it is a hypertonic solution.