URGENT help needed with these chemistry questions?

Question

1. A 250cm^3 solution of NaOH was prepeared. 250cm^3 of this solution required 28.2cm^3 of 0.100 M (mol/dcm3) HCl for nuetralisation. Calculate what mass of NAOH was dissolved to make up the original 250cm^3 solution.

HCl + NaOH -> Nal + H2O

2. What volume of 5M (mol/dcm^3) HCl is required to nuetralise 20kg of CaCO3?

2 HCl + CaCO3 -> CaCl2 + H2O + CO2



im stuck would really appriciate some help thanks :)

Answer 1

1.
250x = 28.2*0.100
x = 28.2*0.100/250
x = 0.01128 M
m = (0.01128 M)(0.25 L)(22.99 + 16 + 1.008)
m = 112.79 mg
2.
CaCO3 ==> 40.08 + 12.01 + 3*16 = 100.09 g/M
28 kg(1 M/0.10009 kg) = 279.7482 M
(279.7482 M)(1 L/4 M) ≈ 69.937 L