MASS
Molar mass of molecular nitrogen.
28 g
How many moles is 2.3 g of phosphorus?
0.074 moles
What is the empirical formula for C6H12O6?
CH2O
The name for the unit equivalent to 6.02 x 1023 representative particles?
Mole
The density of a gas at STP is 0.9 g/L. The name of the gas is _________.
Neon
Molar Mass of Iron (II) Phosphate
357.4 g Fe3(PO4)2
How many moles are equal to 5.82 x 1023 atoms of copper?
0.967 moles
How many oxygen atoms are in 10 formula units of Al2(SO4)3?
120 atoms of oxygen
The mass of a mole of an element
molar mass
What is the percent composition of Iron (III) Oxide?
Fe: 69.9%, O: 30.1%
Mass of 0.02 moles of Beryllium Iodide
5 g BeI2
How many moles are in 150 L of H2 at STP?
6.7 mol H2
The empirical formula of a compound is CH2F. The molar mass is 66.0 g. What is the molecular formula?
C2H4F2
Relative amounts of elements in a compound, by mass.
Percent Composition
How many atoms are in 1.00 mol of glucose, C6H12O6?
1.44 x 1025 atoms
A gas has a density of 0.791 g/L at STP. What is the molar mass of the gas?
17.7 g/mol
How many moles are in 1.2 x 103 g of ammonia, NH3?
71 moles
What is the percent composition for Ca(NO3)2?
24.5% Ca, 17.1% N, 58.5% O
The temperature and pressure at STP
0 deg C and 1 atm (or 101.3 kPa)
Calculate the mass of sulfur in 90.0 g of H2SO4.
29.4 g Sulfur
The mass of 5.00 x 1023 molecules of F2
31.6 g F2
If one animal mole weighs 145 g, how much would a mole of moles weigh?
8.73 x 1025 g
Determine the empirical formula of the compound with the percent composition of:
29.1% Na
40.5% S
30.4% O
Na2S2O3
Lowest whole-number ratio of the atoms or moles of the elements in a compound.
Empirical Formula
What is the molecular formula for a compound that is
49.47% C
5.201% H
28.84% N
16.48% O
and has a molar mass of 194.2 g?
C8H10N4O2 Caffeine