Question

A physician orders 20% kci solution. there are 10% and 50% solutions in stock. how much of each are needed to prepare 100 ml of 20% solution?

Answer 1

To prepare 100 mL of a 20% KCl solution, you will need 75 mL of the 10% solution and 25 mL of the 50% solution.

Step-by-step explanation:

To prepare 100 mL of a 20% KCl solution, we can use a mixture of 10% and 50% KCl solutions. Let's say we need x mL of the 10% solution and y mL of the 50% solution.

First, we can write an equation based on the fact that the total volume of the mixture is 100 mL:

x + y = 100

Next, we can write an equation based on the fact that the total amount of KCl in the mixture is 20% (0.20) of the total volume:

0.10x + 0.50y = 0.20(100)

Simplifying the second equation:

0.10x + 0.50y = 20

Now we can solve the system of equations to find the values of x and y:

x + y = 100 → x = 100 - y

0.10x + 0.50y = 20

Substituting the value of x:

0.10(100 - y) + 0.50y = 20

Simplifying and solving for y:

10 - 0.10y + 0.50y = 20

0.40y = 10

y = 25

Now we can substitute the value of y back into the equation x = 100 - y to find x:

x = 100 - 25

x = 75

Therefore, to prepare 100 mL of a 20% KCl solution, we need 75 mL of the 10% solution and 25 mL of the 50% solution.