Show all your work and make sure to label all the numbers with the correct units if you do, I will give you brainliest, 5 stars, and a thank you:

A: A sample of sulfuric acid has a mass of 15.0 g. How many molecules are in this sample?

B: How many moles of sulfuric acid are present in 45 g of this sample?

C: How much would a .750 mole sample of Ammonium sulfate weigh?

D: What is the mass percent of hydrogen in this sample?