an order is written for 250ml of a 2% solution. you have a 6% solution in stock.

how much stock solution and how much diluent are needed to compound this order.
my answer
166.7ml diluent is added to 83.3 ml stock
is that correct?

1 answer

No, that is not correct. Here's the correct calculation:

Let X be the amount of stock solution needed.
Then (250 - X) is the amount of diluent needed.
Using the equation: % purity of stock solution x Volume of stock solution = % purity of final solution x Total volume of final solution
We get: 6% x X = 2% x 250
Solving for X, we get: X = (2% x 250) / 6% = 83.33 ml
Therefore, the amount of diluent needed is 250 - 83.33 = 166.67 ml.

So the correct answer is: 83.33 ml of the 6% stock solution and 166.67 ml of diluent are needed to compound this order.