The Mole
Mole Mass/Volume
% Composition
Potpourri
100
Avogadro's number of representative particles is equal to one ____.
mole
100
The molar mass of a substance can be calculated from its density alone, if that substance is a(n) ____.
gas at STP
100
The relative amounts of the elements in a compound are expressed as the _________________
percent composition
100
The mass of a mole of HCl is the ____.
molar mass
200
How many moles of silver atoms are in 2.8 x 10^20 atoms of silver?
4.65 x 10^-4 moles
200
What is the number of moles in 400 L of H gas at STP?
17.9 moles
200
What is the percent composition of oxygen in BaCrO?4
25.3 %
200
Which has the highest iron content? FeCl2 or FeO?
FeO
300
How many atoms are in 2.10 mol CO2?
3.79 x 10^24 atoms
300
Find the molar mass of (NH4)2HPO4
132 g/mol
300
Find the % composition of Hydrogen in (NH4)2HPO4
6.82 %
300
Which contains the largest # of atoms, 82.0 g Kr or 0.842 mol C2H4
0.842 mol C2H4
400
Find the mass, in grams, of 1.40 x 10^23 molecules of O2.
7.44 g
400
If the density of a noble gas is 3.741 g/L at STP, that gas is ____.
Krypton
400
What is the percent by mass of oxygen in aspirin, C9H8O4?
35.6 %
400
What is the empirical formula of a substance that is 53.5% C, 15.5% H, and 31.1% N by weight?
C2H7N
500
How many representative particles are in 2.65 g of a molecular compound with a molar mass of 237 g?
6.73 x 10^21 molecules
500
Determine the molar mass of bromine gas.
159.8 g/mol
500
Calculate the molecular formula of a 180g/mol compound which has the empirical formula of CH2O
C6H12O6
500
What is the percent composition of Oxygen, if a sample of NiO with a mass of 51.9 g contains 43.1g Ni?
17.0 % Oxygen
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