Need help with how to solve chemistry problems?

Question

How do you solve the following?

How many moles are in 22grams of argon?
How many grams are in 238 moles of arsenic?
How many moles are in 98.3 grams of Al(OH)3

Answer 1

OK, but you need to look up atomic weights or calculate molar mass.

Grams = Moles x molar mass OR moles x atomic mass

Moles = Grams/(molar mass) OR Grams/(atomic mass)