2. Atoms & Elements

A gas mixture contains 2.0 mol of N_2 and 3.0 mol of O_2. What is the mole fraction of N_2 in the mixture?

How many sulfur atoms are present in 0.45 mol of BaSO4?

How many molecules are present in 13.5 g of sulfur dioxide (SO_2)?

How many silver atoms are present in a 33.0 g bar of silver (Ag)? (Atomic mass of Ag = 107.9 g/mol)

How many atoms are present in 0.375 mol of palladium (Pd) atoms?

How many moles are present in 432 g of Ba(NO3)2?

How many silicon atoms are present in 1.00 g of silicon (Si)? (Atomic mass of Si = 28.09 g/mol)

What is the total number of atoms contained in 2.00 moles of nickel (Ni)?

How many magnesium atoms are present in 1.00 mole of Mg?

One mole of which of these compounds contains two moles of hydrogen atoms?

How many atoms are present in 12 grams (1 mole) of carbon-12?

How many moles are present in 7.5 × 10^{19} molecules of ammonia (NH_3)?

How many molecules are present in 2.50 moles of O_2?

Which of the following solutions contains the same number of moles of KCl as 75.00 mL of a 0.250 M solution of KCl?

One mole of particles of any substance contains how many particles?