Mole/Gram Conversions
How many grams are in 3.5 mol of Ca3(PO4)2?
Molar mass Ca3(PO4)2 = 310.18 g/mol
3.5 mol X 310.18 g/mol = 1085.63 g
How many molecules are in 3.996 mol of C6H12O6?
3.996 mol X 6.02 x 1023 amu = 2.406 x 1024 amu
20g methane (CH4) gas to liters
28 L of methane
What is the percent composition of H2O?
H: 11.1% O: 88.9%
A 15g sample of a compound is found to contain 58.87% sodium and 41.13% sulfur. Calculate the empirical formula of this compound.
Na2S
How many moles are in 79.85 g of Fe2O3?
Molar mass Fe2O3 = 159.7 g/mol
79.85 g / 159.7 g/mol = 0.5 mol
How many moles are in 3.01 × 1024 molecules of (NH4)2SO4?
3.01 × 1024 amu / 6.02 x 1023 amu = 5 mol
120g of C to atoms C
6.0 x 1024 atoms C
A sample of a compound containing only carbon, oxygen, and chlorine is determined to contain 3.01 g C, 4.00 g O, and 17.81 g Cl. What is this compound’s percent composition?
12.1% C, 16.1% O, 71.8% Cl
What is the empirical formula for a sample containing 81.70% carbon and 18.29% hydrogen?
CH3
How many moles are in 85 g of AgNO3?
Molar mass = 169.88 g/mol
85g / 169.88 g/mol = 0.5 mol AgNO3
How many molecules are in 133.45 mol of SO2?
133.45 mol x 6.02 x 1023 = 8.03 x 1025 molecules
3.25 x 1024 atoms Na to grams
124g Na
To three significant digits, what is the mass percentage of iron in the compound Fe2O3?
69.9%
Determine the molecular formula of a compound with an empirical formula of NH2 and a formula mass of 32.06 g/mol.
N2H4
How many grams is 1.2 moles of H2O?
22 g H2O
How many moles of nitrogen are there in 4.3 × 1023 molecules?
0.714 moles
2.06 x 1024 formula units of NaCl to grams
2.00 x 102 g NaCl
What is the percent composition of sodium hydroxide?
Na: 57.48%, O: 40%, H: 2.52%
A sample with a molar mass of 34.00 g/mol is found to consist of 0.44g H and 6.92g O. Find its molecular formula.
H2O2
How many moles are in 62.5 g of sodium sulfate?
0.440 moles Na2SO4
How many cadmium atoms are there in 6.57 × 103 moles?
3.96 x 1027 particles
How many liters would 3.85x1025 atoms of Ne occupy?
1432.6 ≈ 1430 L Ne
What is the percent composition of barium nitrate?
56.54% Ba, 12.54% N, and 30.92% O
What is the empirical formula for a compound that contains 10.89% Mg, 31.77% Cl and 57.34% O?
Cl2MgO8