How many molecules are there in 122 grams of Cu(NO3)2?
3.91 x 10^23 molecules Cu(NO3)2.
100
What is the percentage composition of Cr2O3?
68.4% Cr and 31.6% O
100
An oxide of chromium is found to have the following composition: 68.4% Cr and 31.6% O. Determine the compound's empirical formula.
Cr2O3
200
Calculate the molar mass of H3PO4.
98.0 g/mol
200
How many moles of glucose does 1.2 x 10^24 molecules represent?
2.0 moles of glucose
200
How many grams are there in 7.5 x 10^23 molecules of H2SO4?
120 g of H2SO4
200
What is the percentage composition of CaCl2?
36.1% Ca and 63.9% Cl
200
The percent composition of a compound was found to be 63.5% silver, 8.2% nitrogen, and 28.3% oxygen. Determine the compound's empirical formula.
AgNO3
300
State the name and molar mass of Pb(NO3)2.
Lead (II) Nitrate
331 g/mol
300
How many sodium ions are in 3.0 moles of NaCl?
6.02 x 10^23 sodium ions.
300
How many molecules are there in 24 grams of FeF3?
1.3 x 10^23 molecules FeF3.
300
When a 13.60-g sample of a compound containing only magnesium and oxygen is decomposes, 5.40 g of oxygen is obtained. What is the % composition of this compound?
60.3% Mg, 39.7% O.
300
The empirical formula of a hydrocarbon is found to be CH. Laboratory procedures have found that the molar mass of the compound is 78 g/mol. What is the molecular formula of this compound?
C6H6
400
State the name and molar mass of Ga2(SO4)
Gallium (I) sulfate
235.5 g/mol
400
How many total atoms are in 1.0 moles of H2O ?
1.8 x 10^24 atoms.
400
How many grams are there in 7.4 x 1023 molecules of AgNO3?
210 g of AgNO3.
400
A compound is formed when 9.03 g Mg combines completely with 3.48 g N. What is the % composition of this compound?
72.2% Mg, 27.8% N.
400
A 60.00 g sample of tetraethyl lead, a gasoline additive, is found to contain 38.43 g lead, 17.83 g carbon, and 3.74 g hydrogen. Find its empirical formula
PbC8H20
500
State the name and molar mass of (NH4)2SO4.
Ammonium sulfate
132.2 g/mol
500
How many moles of CaCl2 does 2.41 x 10^24 formula units represent?
4.0 moles of CaCl2
500
How many molecules are there in 230 grams of CoCl2?
1.1 x 10^24 molecules of CoCl2.
500
When a 14.2-g sample of mercury (II) oxide is decomposed into its elements by heating, 13.2 Hg is obtained. What is the % composition of the compound?
7.0% O, 93.0% Hg.
500
The molar mass of nicotine is 162.1 g/mol. It contains 74.0% carbon, 8.7% hydrogen, and 17.3% nitrogen. Determine nicotine's empirical and molecular formulae.