(iii) If the chemist wants to prepare 5.00 litres of the stock solution from concentrated H2SO4 , which is 18.0M, what volume of concentrated acid should be used?

1 answer

It all depends upon what concentration the chemist wants the stock solution. If we call that M, it will be
c1v1 = c2v2
M*5.00L = 18M x v2
substitute M from your problem, which you didn't post, and solve for v2 of the 18.0 M.