2. Atoms & Elements

How many moles of hydrochloric acid (HCl) are present in 500. mL of a 0.300 M solution?

Why is it useful to use moles to measure chemical quantities in chemistry?

How many molecules are present in 2.3 moles of oxygen (O_2)?

How many atoms are present in 5.80 moles of He?

How many moles of water are present in 36 grams of H_2O?

How many moles are present in 29.5 grams of Na (sodium)? (Atomic mass of Na = 23.0 g/mol)

If one penny has a mass of 2.5 g, what is the mass of 1 mole of pennies?

A silver necklace has a mass of 21.6 g. How many moles of silver atoms are present in the necklace? (Atomic mass of Ag = 107.87 g/mol)

How many moles of pyridine (C5H5N) are contained in 3.13 g of pyridine? (Molar mass of C5H5N = 79.10 g/mol)

Why is the mole an important unit to chemists?

The mass of a mole of carbon atoms is 12.011 grams. What is the mass of a single atom of carbon?

How many moles of iron (Fe) are present in 279 g of iron? (Molar mass of Fe = 55.85 g/mol)

If you have 92 grams of nitrogen dioxide (NO_2), how many moles of NO_2 are present?

How many carbon atoms are present in 5 moles of ethane (C_2H_6)?

In chemistry, what does a mole measure?