I've been gone from school for a few days and I could really use some help figuring out how to do these problems-
1) Determine the grams necessary to prepare 100.0 mL of 0.50-N sodium hydroxide.
2) Determine the normality of 3.0 grams of calcium acetate in 200 mL of water.
3) Determine the missing amount in 15.0 mL of 0.20-M sodium hydroxide titrates 10.5 mL of __-M hydrochloric acid.
There are also a few problems like the third one where I have to determine the normality instead of molality, but I'm not sure if that makes a difference.
I'm completely lost, please help! :-\