2. Atoms & Elements

A 0.399 g sample of an unknown gas fills a 550. mL flask at standard temperature and pressure (STP). What is the molar mass of the gas?

Approximately how many grams of Fe2O3 are present in 0.82 mol Fe2O3?

Which of the following is the molar mass of carbon (C)?

A 1.0 mol sample of which of the following compounds has the greatest mass?

How many bromine (Br) atoms are present in 2.50 g of elemental bromine?

How many different elements are present in the chemical formula C6H12O6?

What is the molar mass of ammonia (NH_3)?

How many moles of calcium (Ca) are present in a 425 g sample of calcium?

How many bromide ions (Br^-) are present in 3.50 g of MgBr_2?

What is the mass of 2 moles of HgO?

A sample of an unknown gas has a density of 4.75 g/L at 3.00 atm and 45.0 °C. What is the molar mass of the gas?

What is the mass of one mole of sodium chloride, $NaCl$, to the nearest tenth of a gram?

What is the molar mass of strontium chloride (SrCl_2)?

What is the mass in grams of 1.00 \times 10^6 sodium atoms? (Atomic mass of Na = 22.99 g/mol)