Question

the chemistry lab at the university of Hardwoods keeps two acid solutions on hand. One is 20% acid and the other is 35% acid . how much 20% acid solution and how much 35% acid solution should be used to prepare 25 liters of a 26% acid solution?

Answer 1

hi,
if we take a liter of 20% acid solution ... then that liter is 20% acid
if we take a liter of 35% acid solution ... then that liter is 35% acid

but wt the question ask is to prepare a solution of 26%acid with the volume of 25 liters.

First we can calculate the amount we need for 1 liter.. and then we can multiply it by 25...

if we take "x" amount of 20% the amount of 35% is (1-x) liters
so....
20x + 35(1 - x) = 26
20x + 35 -35x = 26
15x = 9
x = 9/15 liters
x = 3/5 liters
x = 600 ml
so... to prepare a 1 liter solution of 26%acid u need 600 ml of 20% acid
and the amount of 35% acid is 400 ml

but to prepare a solution of 25 liters
u will need
( 600ml x 25) of 20% acid which is = 15 liters
and
(400ml x 25) of 35% acid which is = 10 liters


Hope this will help ya!!!!

Answer 2

where did you get the 400 from

Answer 3

in the beginning I said that if the amount of 20% acid need for i liter is "X" then the amount of 35% acid that will be needed is (1-X) liters....
we got the value 3/5 for "X"
so the amount of 35% is
(1 - X) liters
= (1 -3/5) liters
= 2/5 liters
which is 400 ml
got it ?

Answer 4

oh ok

Answer 5

Did u got the whole explanation now,,,, :-) ?

Answer 6

yes