Molar Mass
What is the molar mass of Chlorine gas? (Cl2)
70.9 g/mol
What is the mass in grams of 4 moles of helium, He?
16.00 g He
Determine the percentage composition of each of the compounds below:
KMnO4
K: 24.74% Mn: 34.77% O: 40.50%
Determine the empirical formulas for compounds with the following percent compositions:
15.8% carbon and 84.2% sulfur
CS2
What is the molecular formula for the compound whose molar mass is 97.0 g/mol and the empirical formula is CH4?
C6H24
What is the molar mass of Carbon Dioxide? (CO2)
44.01 g/mol
How many moles of carbon dioxide, CO2, are in a 22 gram sample of the compound?
0.50 moles CO2
Determine the percentage composition of each of the compounds below:
H2O
H: 11.21% O: 88.79%
Determine the empirical formulas for compounds with the following percent compositions:
40.0% carbon, 6.7% hydrogen, and 53.3% oxygen
CH2O
A compound is analyzed and found to have the empirical formula of CH2O. If the molar mass is 150.15 g/mol what is the molecular formula?
C5H10O5
What is the molar mass of Water? (H2O)
18.02 g/mol
How many moles of hydrogen molecules (H2) are present in 9 x 1023 molecules of hydrogen?
1.49 moles H2
Determine the percentage composition of each of the compounds below:
HCl
H: 2.77% Cl: 97.23%
Polymers are large molecules composed of simple units repeated many times. Thus, they often have relatively simple empirical formulas. Calculate the empirical formulas of the following polymers:
polyethylene; 86% C, 14% H
CH2
A compound containing 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen has an atomic mass of 180g/mol. What is the molecular formula?
C6H12O6
What is the molar mass of Ammonium Sulfate? (NH4)2SO4
132.16 g/mol
What is the volume in L, occupied by 40 grams of argon gas (Ar) at standard conditions?
22.43 L Ar gas
H3PO4, Phosphoric acid, is used in detergents, fertilizers, toothpastes and flavoring in carbonated beverages. Calculate the percent composition to two decimal places of H, P and O in this compound.
H: 3.09%, P: 31.61%, O: 65.31%
Polymers are large molecules composed of simple units repeated many times. Thus, they often have relatively simple empirical formulas. Calculate the empirical formulas of the following polymers:
Orlon; 67.9% C, 5.70% H, 26.4% N
C3H3N
A compound contains 87.4% nitrogen and 12.6% hydrogen. If the molecular mass of the compound is 32.05 g/mol, what is the molecular formula?
N2H4
What is the molar mass of Glucose? (C6H12O6)
180.18 g/mol
How many molecules of ethane gas, C2H6 are in 15 grams of the compound?
3.00 x 1023 molecules of C2H6
What is the percent composition by mass of aspartame (C14H18N2O5), the artificial sweetener NutraSweet?
C: 57.14%, H: 6.12%, N: 9.52%, O: 27.21%
A compound was found to contain 32.65% Sulfur, 65.3% Oxygen and 2.04% Hydrogen. What is the empirical formula of the compound?
SO4H2
A major textile dye manufacturer developed a new yellow dye. The dye has a percent composition of 75.95% C, 17.72% N, and 6.33% H by mass with a molar mass of about 240 g/mol. Determine the molecular formula of the dye.
C15H15N3