Question: How many atoms are in 1.50 moles of fluorine gas?

Answer: fluorine is a diatomic molecule so multiply by 2.

(2)(1.50 mol)(6.02x10^23 atoms/mol) = 1.81x10^24 atoms

Question: How many atoms are in 5.80 moles of Helium?

Answer: 5.80 mol He

10^23 atoms He/ 1 mol He. This cancels out moles, leaving 3.49*10^24 atoms He.

Question: Mass is used as a method of counting atoms.

Answer: true

Question: The chemical formula clearly indicates the relationship between the mass of each element in the formula.

Answer: false

Question: one mole of oxygen has mass of ___ g

Answer: When you are discussing oxygen as the free, uncombined element, then you are discussing oxygen gas, the formula of which is O2 and the molecular weight of which is 32. (which, as you well know, comes from 16 x 2).

Question: The mass of one mole of carbon dioxide is ________ g.

Answer: 44.01

Question: What is the molar mass of aluminum sulfate?

Answer: 342.2 g/mol

Question: Calculate the molar mass of ammonium carbonate.

Answer: 96.09 g/mol

Question: One mole of (NH4)2HPO4 contains how many moles of hydrogen atoms?

Answer: 9

Question: The chemical formula CuBr2 indicates that this compound is composed of 1 gram of copper and 2 grams of bromine.

Answer: false