(b) Given a bottle containing 9M-H2SO4 calculate the number of :-

(i) Grammes of the acid in 1 dm3
(ii) Moles of the acid in 50cm3
(iii) If 20cm3 of the acid were to be diluted to 1M, How many milliliters of distilled water would be needed?

1. Given 9 M H2SO4. M = moles/dm^3 = moles/L; therefore you have 9 moles. grams = moles x molar mass = ?

2. You have 9 moles H2SO4 in 1000 cc; therefore, you have
9 x (50/1000) = ? moles in 50 cc.
3. Use the dilution formula.
mL1 x M1 = mL2 x M2
20 mL x 9 M = mL2 x 1 M
Solve for mL1. That is the TOTAL volume of the solution. Technically, you can't calculate the amount of water that must be added since volumes are not additive. For practical purposes, however, you know the total volume is 180 cc and you started with 20 so you would add 160 cc water. The correct way to answer the question is "take 20 mL of the 9 M H2SO4 and add enough water to make a total of 180 cc".