How many milliliters of water must be added 100.0ml of 4.50MHBr to make a solution that is 0.250MHCl

The answer to your question is 1.8 liters (maybe we have to consider that there are 100 ml of the original solution so the volume of water will be 1.7 l)

Explanation:

Data

Volume 1 = 100 ml

Concentration 1 = 4.5 M

Concentration 2 = 0.25 M

Volume 2 = ?

Process

1. - Calculate the number of moles in solution 1

Molarity = moles/volume

-Solve for moles

moles = Molarity x volume

-Substitution

moles = 4.5 x 0.1

-result

moles = 0.45

2. - Calculate Volume 2

Volume = moles/concentration

-Substitution

Volume = 0.45 / 0.25

-Result

Volume = 1.8 l

3. - Conclusion

There must be added 1.8 l of water to the 4.5 solution