The Mole & Avogadro’s Number
What is Avogadro’s number?
6.02 × 10²³
What is the molar mass of H₂O?
18.02 g/mol
What volume does 1 mole of any gas occupy at STP?
22.4 L
What is the percent composition of hydrogen in H₂O?
11.2% H
How many grams are in 0.50 moles of NaCl?
29.2 g
How many atoms are in 2.5 moles of helium?
1.51 × 10²⁴ atoms
What is the molar mass of CaCl₂?
110.98 g/mol
How many liters does 0.500 moles of O₂ occupy at STP?
11.2 L
What is the empirical formula of a compound with 75% C and 25% H?
CH₄
How many molecules are in 2.0 moles of NH₃?
1.20 × 10²⁴ molecules
How many moles are in 1.50 × 10²⁴ molecules of CO₂?
2.49 moles
How many moles are in 88.0 g of CO₂?
2.00 moles
How many moles are in 67.2 L of N₂ gas at STP?
3.00 moles
What is the percent composition of oxygen in CO₂?
72.7% O
What is the molecular formula of a compound that is 56.38% P and 43.62% O, with a molar mass of 219.9 g?
P₄O₁₀
How many molecules are in 0.75 moles of H₂O?
4.52 × 10²³ molecules
How many grams are in 0.250 moles of Na₂SO₄?
35.5 g
If you have 5.00 L of CO₂ at STP, how many molecules are present?
1.34 × 10²³ molecules
Determine the empirical formula for a compound that is 40% C, 6.7% H, and 53.3% O.
CH₂O
How many liters are occupied by 3.25 moles of a gas at STP?
72.8 L
If you have 3.0 × 10²⁴ atoms of sulfur, how many moles is this?
4.98 moles
Convert 3.5 moles of CH₄ to grams.
56.0 g
If a gas occupies 22.4 L at STP, what is its molar mass if its mass is 44.0 g?
44.0 g/mol (CO₂)
A compound contains 27.3% C and 72.7% O. What is its empirical formula?
CO
If a gas has a mass of 32.0 g and occupies 22.4 L at STP, what is its molar mass?
32.0 g/mol (O₂)