by **CaitlanK** » Thu Jul 28, 2011 4:05 am

The directions for mixing a 250mg/5ml liquid antibiotic state when 80ml of water are added to the contents of the bottle the resulting volume is 150ml. determine concentration of the drug in mg/5ml if only 40ml of water were added?

i already determined the total mg of the drug in the bottle which is 7500mg, i then determined the powder volume of the drug in the bottle which was 70ml. then i had to figure out the volume of the new product, which i solved by:

New Product(NP)=D+PV

NP= 110 ml

At the end of this problem i have to write out the new concentration as total mg drug in bottle/volume of new product

which would look like this 7500mg/110ml, in my textbook they converted that into 6.82mg/ml then converted that to 341mg/5ml.

My question is how did they get 7500mg/110ml to convert to 341mg/5ml.

Help im not understanding the conversion on the last question!