Chapter 10 Review
Which of the following sets of empirical formula, molar mass, and molecular formula is correct:
a) CH, 78 g, C13H13, or
b) CH4N, 90 g, C3H12N3?
What is the empirical formula of a compound that is 40% sulfur and 60% oxygen by weight?
Avogadro’s number of representative particles is equal to one ____.
The molar mass of a certain gas is 49 g. What is the density of the gas in g/L at STP?
A 22.4 L sample of which of the following substances, at STP, would contain 6.02 x 1023
representative particles: a) oxygen, or b) gold?
What is the molar mass of AuCl3?
The lowest whole-number ratio of the elements in a compound is called the ____.
What is the number of moles in 500 L of He gas at STP?
What is the percent composition of chromium in BaCrO4?
How many molecules are in 2.10 mol CO2?
How many hydrogen atoms are in 5 molecules of isopropyl alcohol, C3H7O?
If the density of an unknown gas Z is 4.50 g/L at STP, what is the molar mass of gas Z?
Which of the following compounds have the same empirical formula: a) C7H14 and C10H20, or
b) C6H12 and C6H14?
Which of the following is NOT an empirical formula: a) C2N2H8, or
What is the density at STP of the gas sulfur hexafluoride, SF6?
Determine the mass in grams of 3.10 x 1023 molecules of F2.
b) C3H8O?
Chapter 10 Review
1)
How many molecules are there in 24 grams of FeF3?
2)
How many molecules are there in 450 grams of Na2SO4?
3)
How many grams are there in 2.3 x 1024 atoms of silver?
4)
How many grams are there in 7.4 x 1023 molecules of AgNO3?
5)
How many grams are there in 7.5 x 1023 molecules of H2SO4?
6)
How many molecules are there in 122 grams of Cu(NO3)2?
7)
How many grams are there in 9.4 x 1025 molecules of H2?
8)
How many molecules are there in 230 grams of CoCl2?
9)
How many molecules are there in 2.3 grams of NH4SO2?
10)
How many grams are there in 3.3 x 1023 molecules of N2I6?
11)
How many molecules are there in 200 grams of CCl4?
12)
How many grams are there in 1 x 1024 molecules of BCl3?
13)
How many grams are there in 4.5 x 1022 molecules of Ba(NO2)2?
14)
How many molecules are there in 9.34 grams of LiCl?
15)
How many grams do 4.3 x 1021molecules of UF6 weigh?
16)
How many molecules are there in 230 grams of NH4OH?
17)
Determine the empirical formula for each compound.
a) Phosphoric acid is found in some soft drinks. A sample of phosphoric acid contains 0.3086 g
of hydrogen, 3.161 g of phosphorus, and 6.531 g of oxygen.
b) A compound consists of 72.2% magnesium and 27.8% nitrogen by mass.
c) Glucose contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass
18)
Determine the molecular formula for each compound.
a) A compound has an empirical formula of NO2 and a molar mass of 92.02 g/mol.
b) The compound methyl butanoate (an ester) smells like apples. It’s percent composition is:
58.8 % C, 9.9 % H, and 31.3 % O. If it’s molecular mass is 306 g/mole, what is the molecular
formula?
c) Epinephrine (adrenaline) is a hormone secreted into the bloodstream in times of danger and
stress. It is 59.0% carbon, 7.1% hydrogen, 26.2% oxygen, and 7.7% nitrogen by mass. Its molar
mass is about 180 g/mol.
Chapter 10 Review Answers
1)
How many molecules are there in 24 grams of FeF3? 1.28 x 1023 molecules
2)
How many molecules are there in 450 grams of Na2SO4? 1.91 x 1024 molecules
3)
How many grams are there in 2.3 x 1024 atoms of silver? 421 grams
4)
How many grams are there in 7.4 x 1023 molecules of AgNO3? 209 grams
5)
How many grams are there in 7.5 x 1023 molecules of H2SO4? 122 grams
6)
How many molecules are there in 122 grams of Cu(NO3)2? 3.92 x 1023 molecules
7)
How many grams are there in 9.4 x 1025 molecules of H2? 312 grams
8)
How many molecules are there in 230 grams of CoCl2? 1.07 x 1024 molecules
9)
How many molecules are there in 2.3 grams of NH4SO2? 1.69 x 1022 molecules
10)
How many grams are there in 3.3 x 1023 molecules of N2I6? 430 grams
11)
How many molecules are there in 200 grams of CCl4? 7.82 x 1023 molecules
12)
How many grams are there in 1 x 1024 molecules of BCl3? 195 grams
13)
How many grams are there in 4.5 x 1022 molecules of Ba(NO2)2? 17.1 grams
14)
How many molecules are there in 9.34 grams of LiCl? 1.33 x 1023 molecules
15)
How many grams do 4.3 x 1021 molecules of UF6 weigh? 2.51 grams
16)
How many molecules are there in 230 grams of NH4OH? 3.96 x 1024 molecules
17)
a- H3PO4
b- Mg3N2
c- CH2O
18)
a- N2O4
b- C5H10O2
c- C9H13NO3