Question

How many liters of water must be added to 50L of 30% acid solution in order to produce a 20% acid solution?

Answer 1

25L

Answer 2

care to explain, vicky?

Answer 3

yes please i dont know how you got that

Answer 4

given 30% solution which means 30% of the solution is acid . so in the given 50L , about 15L is acid . we need to make it 20% , this is when 15L is the 20% of something . simple maths tells us that 20% of 75L is 15L so we need to add another 25 L to the 50L to make it 75L

Answer 5

A way to approach this problem (and any similar dilution problem) is this: you are not changing the moles of acid inside the solution so you can write an equation relating the moles of acid before and after dilution:\[M_1*V_1 = M_2*V_2\]where M is the % of acid, and V is the total volume of the solution

Answer 6

im so conufused

Answer 7

\[30*50 = 20*(50+x)\] solving for x gives us the volume of water added in liters

Answer 8

oh

Answer 9

(30/100)*50=15
(100/20)*15=75
75-50=25

Answer 10

oh

Answer 11

wait so 25 is the right answer

Answer 12

right

Answer 13

oh ok thank you so much