a student nee 10% hydrochloric acid for a chemistry experiment. how much 5% acid should be mixed with 60 ml of 20% acid to get 10% solution.

Question

a student nee 10% hydrochloric acid for a chemistry experiment. how much 5% acid should be mixed with 60 ml of 20% acid to get 10% solution.

Answer 1

We know that 5% of beaker X is acid, and 20% of beaker Y is acid. 

Beaker Y is 60ml.

We don't know he amount of overall liquid in X, so we will say that the is x ml in it.

If we are dumping the entire contents of X and of beaker Y together then the final amount of liquid will be

(x + 60)ml

 

If we think about this in terms of acid:

5%x +20%(60ml) = the acid we need,    since acid +acid = acid, which is then

5%x +20%(60ml) =10%(x+60)

change percents to usable decimals

 

0.05x + 0.2(60) = 0.1(x + 60) and then solve for x.