2. Atoms & Elements

How many moles are present in 55 g of NaCl?

What is the significance of Avogadro's number? Avogadro's number is the number of -

How many moles of carbon atoms are present in 18 g of carbon (C)?

What is the quantity, in moles, of CH3OH present in 150.0 mL of a 0.210 M CH3OH solution?

One half of a mole of atoms would contain how many atoms?

A solution is prepared by mixing 2.0 mol of hexane (C6H14) with 3.0 mol of heptane (C7H16), assuming ideal behavior. What is the mole fraction of hexane in the solution?

How many molecules of CH_4 are present in 48.2 g of this compound?

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

How many atoms of neon are present in 1.30 moles of neon?

How many atoms are present in 1.5 moles of helium (He)?

How many moles of CH3OH are present in 50.0 mL of a 0.400 M CH3OH solution?

How many atoms of potassium are present in $1\mathrm{mol}$ of potassium ($K$)?

How many aluminum atoms are present in 3.78 g of aluminum (Al)? (Atomic mass of Al = 26.98 g/mol)

How many moles of HCl are present in 75.0 mL of 0.150 M HCl solution?

How many moles of SO_2 contain 8.02 × 10^{21} atoms of oxygen?