Doctor's order.

Question

A doctor has ordered 325 mg of atropine. The drug is available as a solution that contains .50 g of atropine per mL. How many mL of the solution would the patient need ?

 

I have (325 mg)/(.50ml) = 650

Answer 1

The solution of atropine available contains 0.5g of atropine or 500mg/ml. We need 325mg:

500mg:1ml=325mg : X ml

X=325/500=0.65ml

Answer 2

Best way to answer this is by using dimensional analysis:

 

325 mg atropine needed*(1 gm/1000 mg)*(1 ml/0.5 gms atropine)

 

All the units cancel out except for ml.

 

Answer is 0.65 ml of solution