What mass of Ca(OH)2 is required to prepare 200mL of 0.2N solution?

Answer 1

See your last post. M = 2 x N for Ca(OH)2.
Mols =M x L
g = mols x molar mass
Post your work if you get stuck.

Answer 2

I get 0.1 for Molarity.

N=Molarity*Equivalent

Equivalent=2 because you have two OH groups.

N=0.2

Molarity=0.1

0.2L*0.1M=moles

Moles*(molecular weight)=mass needed in grams