Chemistry help: Desperate?

Question

Dear Yahoo Answers,
This is a really hard chem question and I am having difficulty with it. Please Help.

An Acid spill involves 2000 Litres of HCl solution that has a concentration of 6 moles of HCl per litre. Solid Ca(OH)2 is used to neutralize the spill. Calculate the mass of the calcium hydroxide required to do the job according to the equation;
Ca(OH)2 +2HCl = 2H2O + CaCl2 (4 marks)

I really need to figure this out and see the process that needs to be taken so any contribution will be appreciated.

Thanks.

Answer 1

To begin with, we determine the moles of HCl:

2000 X 6 = 12000 moles of HCl

Then from the equation we determine how many moles of Ca(OH)2 we need. In this case, 6000 moles (12000/2).

to determine the amount of Ca(OH)2 we calculate the mass in grams of one mole, and multiply it by 6000.
Ca 2O 2H
40.08+32+2=74.08 g/mole
simply multiply 74.08 by 6000 and you have the answer.

Answer 2

Atomic weights: Ca=40 O=16 H=1 Ca(OH)2=74

Let the solution be called S.

2000LS x 6molHCl/1LS x 1molCa(OH)2/2molHCl x 74gCa(OH)2/1molCa(OH)2 = 444,000g = 444 kg Ca(OH)2