A stock solution of 10M NaOH is prepared. From this solution, you need to make 250mL of 0.375M solution. How many mL will be required?The answer if 9.4mL but I don't know how to get that.
2 Answers
thilina-g | College Teacher | (Level 1) Educator
suppose, V ml is the volume required from the stock solution,
and then the number of moles in that V will be, n1
n1 = 10 mol/dm3 x (v/1000)
n1 = v/100
This amount of moles are in 250mL of 0.375M solution,
therefore,
0.375 = (v/100)/250 x 1000
0.375 = v/25
v = 9.375 mL
But the amount you can measure by a measuring cylinder (10 mL) is 9.4 mL. (0.1 mL accuracy)
Therefore the answer is 9.4 mL
qq765598575 | Student, Grade 10 | eNotes Newbie
There are two kinds of solutions:the one we have(10 M),and the one we need(0.375M).What is the same in these solutions? the amount of substance of solute.
Assuming that xL is required.
10x=0.375*0.25
the answer is 0.009375L=9.375mL.
And you need a graduated container, such as a cylinder
It can contain 10mL.
but the smallest scale is 0.1mL.
9.375mL in it and you can only read 9.4 ml.
it is the container that makes difference.