+0  
 
0
142
2
avatar

how many milliliters of water should be added to 1.5 liter of a 20% w/v solution to prepare one containing 12% w/v solute?

 Nov 17, 2020
 #1
avatar+116125 
+1

Let x be the mL of water we are looking for.....and pure water = 100% water  = 1.00

 

20% solution = 80% water=  .,80

12% solution = 88% water = .88

 

And 1.5 L  =  1500mL

 

So we have

 

x (1.00)  +  1500 (.80) =  .88 ( 1500 + x)     simplify

 

1x  + 1200 =  1320  + .88x

 

1x - .88x  = 1320 - 1200

 

.12x = 120      divide both sides by .12

 

x = 1000mL  of   water

 

cool cool cool

 Nov 17, 2020
 #2
avatar
+1

Liters of water needed =L

 

20% * 1.5 =12% * [1.5 + L], solve for L

 

L = 1 Liter x 1000 =1000 mL of water needed.

 Nov 18, 2020

9 Online Users

avatar
avatar