2. Atoms & Elements

How many atoms of gold (Au) are present in 4 moles of gold?

If you have 24 grams of carbon (atomic mass = 12 g/mol), how many moles of carbon do you have?

What is the approximate mole fraction of neon (Ne) in dry air at sea level?

How many moles of Ba(NO3)2 are present in 0.25 L of a 2.00 M Ba(NO3)2 solution?

How many molecules are present in 23 moles of oxygen (O_2)?

Which of the following samples contains approximately 2 moles of particles?

How many atoms of carbon are present in 0.68 moles of carbon?

How many moles of Cl are present in one mole of CaCl2?

A 3.00 mole sample of K_2S contains how many atoms of potassium?

How many atoms are present in 179.0 g of iridium (Ir)? (Atomic mass of Ir = 192.2 g/mol)

How many phosphorus atoms are present in 158 kg of elemental phosphorus (P)?

Which of the following tasks most likely involves a calculation that uses moles?

How many atoms are present in a 12.0 g sample of lithium (Li)? (Atomic mass of Li = 6.94 g/mol)

What is the mass in grams of one mole of any pure substance called?

A sample contains 1.25 grams of CH_4 and no other substances. What is the mole fraction of O_2 in this sample?