help me pls...?

Question

How much water must be added to 10 liter of 6 M solution to make it 3.8 M?

tell me what to do..

Answer 1

Ok, use the formula: No.of moles = concentration x volume
N = C x V

Now manupilate it : C(initial) x V(initial) = C(final) x V(final)

Then input in the values: 6 x 10 = 3.8 x V(final)

Finally, volume required : V(final) = 6 x 10 / 3.8 = 15.789 litres

Therefore you must add in : 15.789 - 10 = 5.789 litres of water

Answer 2

M1V1 = M2 V2

now fill in what you know and solve for what you don't