20 % of solution how much?

Question

make a solution where the disinfectant fluid is to be diluted with water to make a 20%solution you have 100ml of the disinfectant fluid . How much water should you add to the 100 ml of the disinfectant fluid to make a 20 % total solution? show calculations

Answer 1

1) Find 20% of 100ml
2) (0.2 x 100) = 20
3) Add 20ml of water

Answer 2

Amount of water that you should add to the 100 mL of disinfectant fluid to make the fraction of disinfectant be 20% = 0.2 V

total volume =100/0.2 =500 mL

add 500 -100 = 400 mL

Answer 3

simple ratio and porportion problem.

20% : 100% :: 100ml : X

20%.... is to 100% as 100ml is to X ml.
extreme.......mean......mean ......extreme
multiply the means (the inner two) and the extremes (outer two)

multiply the means 20*X = 20X
multiply the extremes 100*100 = 10000
means on one side of the equal sign
extremes on the other side of the equal sign.
20X = 10000
divide both sides by 20

20X / 20= 10000 / 20
X=500 mL

500 ml. of 20% solution can be made out of 100 ml of 100% solution.

Worked a ton of these type problems when in nursing school (wife not me) Guess you see who did her math for her.

The other way to work it is as a ration problem

20% / 100% = 100ml /X
the % signs canceal out

20 /100 = 100ml / X
multiply both sides by X
(20 /100) X = 100ml
divide both sides by 20/100

X = 100ml * (100/20)
X = 10000ml / 20
X = 500 ml.
either way works. If you are doing this for nursing they usually prefer the porportion set up. If you are doing this for Chemistry or Math usually prefer ratio.

Answer 4

simple......... follow this equation:
let x be the total amount of solution
%solution = 100(100ml/x)
20%= 100(100ml/x)
20x = 10000
x = 500ml
so 500ml -100ml
= 400ml
the amount of water u need to add to make a 20 % solution from a 100ml disinfectant fluid

Answer 5

(volume of disinfectant / volume of solution) x 100
= %disinfectant
volume of disinfectant =100ml
%disinfectant =20

therefore, volume of solution = 100ml x 100/20 = 500ml

therefore vol of water = 500ml - 100ml =400 ml

Answer 6

you must add to 100 mL enough water to make the fraction of disinfectant be 20% = 0.2 of total volume

So total volume =100/0.2 =500 mL

So add 500 -100 = 400 mL

Answer 7

Let x = no. of ml of pure water.

20%(100 + x) = 100
100 + x = 500
x = 400

Answer: 400 ml of water

Proof:
= 100 / (100 + 400)
= 1/5 or 0.2 or 20%

Answer 8

let amt of solute(disinfectant) = 100ml
concentration = 20% = (volume of solute)/(volume of solution)*100
= ((volume of solute)/(volume of solvent + volume of solute))*100

thus 20 = (100*100)/(100+x)
thus 2000 + 20x = 10000
thus 20x = 8000
x = 400

thus, volume of solvent i.e water = x = 400 ml