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

`V_(syrup)= 60ml` and
`V_(elixir)= 40ml`

Step-by-step 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(mg)/(ml)*100ml = 200mg`

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

`V_(elixir)= (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!