Question

Theophylline, an asthma medicine, is to be prepared from an elixir with a drug concentration of 5 mg/mL and a cherry-flavored syrup that is to be added to hide the taste of the drug. How much of each must be used to prepare 100 milliliters of solution with a drug concentration of 2 mg/mL?

Answer 1

Answer:

$V_{syrup}= 60ml$ and $V_{elixir}= 40ml$

Explanation:

Well, we need 100ml of solution, with a concentration of 2mg/ml. So the total amount of drug we need is :

$M_{drug} =2\frac{mg}{ml}\times100ml = 200mg$

But the drug concentration is  5mg/ml, so the amount of elixir needed to get 200mg of drug is:

$V_{elixir}= \frac{200mg}{5mg/ml}=40ml$

And so the amount of cherry flavoured syrup needed is:

$V_{syrup}= 100-40 = 60ml$

Hope my answer helps.

Have a nice day!