Question

A nurse wants to add water to 10 ounces of a 10% solution of benzalkonium chloride to dilute it to an 8% solution. how much water must she add? (hint: water is 0% benzalkonium chloride.)

Answer 1

To dilute a 10% benzalkonium chloride solution to an 8% solution, the nurse must add 2.5 ounces of water to the initial 10 ounces of the solution.

Step-by-step explanation:

The question involves the dilution of a 10% benzalkonium chloride solution to a 8% solution. The initial amount of the solution is 10 ounces. To find out how much water must be added to dilute the 10% solution to an 8% solution, use the following steps:

1. Let x represent the amount of water (which has a 0% concentration of benzalkonium chloride) to be added.
2. The amount of benzalkonium chloride in the original solution is 10% of 10 ounces, which equals 1 ounce.
3. After adding x ounces of water, the total volume of the solution becomes 10 ounces + x ounces.
4. Since the benzalkonium chloride remains constant at 1 ounce, the new percentage should be 1 ounce divided by the total volume of the solution (10 + x ounces).
5. The equation comes from the definition of percentage: (1 / (10 + x)) × 100 = 8%.
6. Solving for x, we get x = 2.5 ounces.

Thus, the nurse must add 2.5 ounces of water to the solution to achieve the desired concentration.