Question

Please help!

A chemist dissolves 1.000 x 10^3 g of potassium hydroxide in enough water to make 1.5 L of stock solution. The chemist later wants 2.00 x 10^2 mL of 0.10 M potassium hydroxide. How much stock solution does the chemist need in order to make this second solution?

Answer 1

c1V1=c2V2

Answer 2

simply use M1V1=M2V2 this concept is for this type of questions here v= volume , m= molarity

Answer 3

first you need to get amount of potassium hydroxide from mass:
n=m/M
then you calculate concentration
c=n/V
then you have been given the amount of solution you need and concentration so you just put it in c1V1=c2V2
V1= c2V2/c1

Answer 4

c1 = 16,66 M
so V1= 0,1M * 0,2 dm3 / 16,66M=1,2 * 10^-3 dm3 or 1,2 mL

Answer 5

this concept is very importannt in day to day lyf.,.

Answer 6

How did you get C1 = 16,66M?

Answer 7

c=n/V
n=m/M

Answer 8

So 1000g of KOH = 16,66 M?

Answer 9

n= 1*10^3g / 40 gmol-1 = 25 mol
c= 25 mol/1,5 dm3 = 16,66 M