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Paul Barron
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use, please contact Dave Erb dave_erb@stao.org
Virtual Library ID: 1150
Course: SCH3U-2
The next two questions refer to the following equation
2 SO2(g) + O2(g)
2 SO3(g)
1.
The number of moles of oxygen required to react with 0.25 mol of SO 2 is
a)
0.125
2.
The mass of SO3 produced by the reaction of 8.0 g of O2 is
a)
8.0 g
3.
Sulfur (S8) reacts with oxygen (O2) and produces sulfur trioxide (SO3) according to the
following balanced equation
S8(s) + 12 O2(g)
8 SO3(g)
b)
b)
0.25
20 g
c)
c)
0.50
40 g
d)
d)
0.34
80 g
e)
0.062
e)
160 g
How many moles of oxygen molecules must react to produce 320 g of sulfur trioxide?
a)
4.00
b)
6.00
c)
24.0
d)
4.
The combustion of acetylene is represented by the following balanced chemical equation
2 C2H2(g) + 5 O2(g)
48.0
4 CO2(g) + 2 H2O(g)
What mass of carbon dioxide (CO2) can the complete burning of 26.0 g of acetylene (C2H2)
produce?
a)
22.0 g
b)
44.0 g
c)
88.0 g
d)
5.
Oxygen may be prepared in the laboratory by heating potassium chlorate. The balanced
equation is
2 KClO3(s) + energy
176 g
2 KCl(s) + 3 O2(g)
The decomposition of 61 g of potassium chlorate produces 24 g of oxygen and
potassium chloride.
a)
16 g
b)
37 g
c)
75 g
d)
85 g
g of
6.
When 10 mol of potassium chlorate (KClO3) is completely decomposed by heating
2 KClO3
2 KCl + 3 O2
the number of moles of oxygen produced is
a)
3 b)
10
c)
7.
Consider the equation
Fe3O4 + 4 H2
15
d)
30
3 Fe + 4 H2O
The number of moles of hydrogen required to completely react with 3.0 mol of iron oxide
(Fe3O4) is
a)
9 b)
12
c)
3
d)
8.
P reacts with Q according to the equation
4
P + Q
R + S
If 13 g of P react with 14 g of Q to produce 15 g of R, how many grams of S are produced?
a)
11 b)
12
9.
Potassium and sulfur react such that 7.8 g of potassium react completely with 3.2 g of sulfur.
If 10 g of potassium react with 10 g of sulfur, approximately how much product is obtained?
a)
10 g
b)
c)
12 g
13
c)
d)
14 g
14
d)
e)
16 g
15
e)
18 g
10. Given the following balanced equation
Fe2O3(s) + 3 CO(g)
2 Fe(s) + 3 CO2(g)
How many moles of iron will be produced if 6.0 mol of CO(g) react?
a)
2.0
b)
4.0
c)
6.0
d)
12
11. Hydrogen gas reacts explosively with oxygen gas producing water vapour. What mass of
oxygen gas would be required to totally consume 1.00 g of hydrogen gas in this reaction?
a)
16.0 g
b)
32.0 g
c)
1.00 g
d)
36.0 g
e)
8.00 g
12. The ratio of hydrogen to oxygen, by mass, in H2O (water) is
a)
1:8 b)
2:1
c)
1:2
d)
8:1
13. If 3.00 g of CaSO4.3 H2O is heated strongly for 10 minutes, what mass of residue salt will
remain after heating?
a)
2.15 g
b)
3.00 g
c)
0.855 g d)
1.19 g
e)
0.00 g
14. Which statement is not true about the following equation
2 C6H6 + 15 O2
12 CO2 + 6 H2O
a) it is balanced
b) C6H6 is a reactant
c) there are 8 hydrogen atoms among the products
d) the number 15 is a coefficient
e) there are 30 oxygen atoms among the products
The next two questions relate to the following situation.
Assume that a Bunsen burner is burning pure gaseous methane, CH 4, with sufficient oxygen
to form the products carbon dioxide gas, CO2, and water, according to the following
equation
CH4 + 2 O2
CO2 + 2 H2O + heat
15. When 8.0 g of methane, CH4 burn, how many moles of water will be produced?
a)
0.50
b)
1.0
c)
2.0
d)
17
e)
36
16. When 8.0 g of methane CH4 burn, the number of grams of carbon dioxide (CO2) produced is
a)
0.50
b)
11
c)
14
d)
22
e)
28
1.
If 12.0 g of carbon react with oxygen to form 44.0 g of carbon dioxide
a) What mass of oxygen is required?
b) How much carbon is required to react with 67.0 g of oxygen?
c) How much carbon dioxide will be formed?
d) Why does the above support the Law of Conservation of Mass?
2.
Ethanol (C2H5OH) burns in oxygen (O2) to produce carbon dioxide, (CO2) and water (H2O)
as products, as shown below
C2H5OH + 3 O2
2 CO2 + 3 H2O
a) How many moles of CO2 would be produced if five moles of O2 are completely
consumed?
b) How many grams of oxygen are needed to completely react with 100 g of ethanol?
3.
2.0 g of hydrogen gas react with exactly 16.0 g of oxygen gas to form water vapour.
a) How many grams of oxygen will react with 5.8 g of hydrogen?
b) How many grams of water will be formed in part a)?
c) Why do parts a) and b) illustrate the Law of Constant Composition?
4.
For the reaction of aluminum sulfate with water to produce aluminum hydroxide and
sulfuric acid:
a) Write a balanced chemical equation for the reaction
b) How many moles of sulfuric acid could be produced from five moles of aluminum
sulfate?
5.
From the following reaction
5 KI + KIO3 + 6 HNO3
6 KNO3 + 3 I2 + 3 H2O
Calculate the mass of KI which must be consumed in order to produce 500.0 g of I 2.
6.
What mass, in grams, of calcium reacting with hydrochloric acid will be required in order to
produce 26 g of hydrogen gas along with a certain quantity of calcium chloride?
7.
Sulfuric acid reacts with potassium carbonate as follows
H2SO4 + K2CO3
K2SO4 + H2O + CO2
a) What mass of potassium carbonate was consumed if 7.84 g of sulfuric acid were used?
b) What volume of carbon dioxide gas was produced at S.T.P. using the 7.84 g of acid?
8.
Determine the mass of calcium phosphate produced by the reaction of 5.00 g of calcium
reacting in excess phosphoric acid.
9.
The following equation shows the burning of methane in oxygen
CH4 + 2 O2
CO2 + 2 H2O
If 400 g of methane and 200 g of oxygen are mixed and ignited, which reactant is left over,
and how many grams of it remain?
10. Using the given equation
P2O5 + 3 H2O
2 H3PO4
a) Determine how many moles of water you would need to start with in order to produce 6
mol of H3PO4.
b) Determine the mass of 12 mol of P2O5.
11. A power generating station just west of Toronto consumed 1,000,000 kg sample of coal in
February. This sample contains 5% sulfur (by mass). Sulfur burns to produce sulfur dioxide
which then reacts with rain water to produce sulphurous acid (acid rain). Each 20 g of acid
rain kills 1 m2 of vegetation.
a) How much vegetation would be "killed" when this sample of coal is consumed?
b) What are the advantages and disadvantages of burning this sample of coal?
c) Suggest possible ways of reducing such sulfur dioxide emissions.
MOLE PROBLEMS
1.
Determine the number of atoms in 4.8 mol of carbon.
2.
How many atoms of oxygen are there in 4.00 mol of potassium chlorate, KClO 3?
3.
What is the total number of atoms in 1 mol of Al2(SO4)3?
4.
Calculate the number of atoms in 30.0 g of Li.
5.
Calculate the actual number of atoms contained in 4.4 x 10 -2 g of carbon dioxide.
6.
Determine the mass represented by 3.01 x 1020 atoms of sulphur.
7.
Determine the mass of 1.204 x 1022 atoms of potassium.
8.
What is the mass of 1.8 x 1021 molecules of O2?
9.
Calculate the mass represented by a single molecule of carbon monoxide gas.
10. Calculate the mass in grams of a single atom of oxygen.
11. It is found that 6.0 g of element X contain 2.0 x 10 22 atoms. Determine the molar mass of
element X.
12. Calculate the mass represented by 10.0 mol of calcium hydroxide.
13. Determine the mass represented by 10.0 mol of magnesium nitrate.
14. What is the mass of 0.782 mol of barium?
15. Calculate the number of moles of Li in 15.0 g of Li.
16. Calculate the number of moles of molecules contained in 4.6 x 10-2 g of ethanol. (CH3CH2OH)
17. Determine the number of moles represented by 5.62 g of oxygen gas (O2) .
18. Calculate the number of moles of molecules contained in 9.81 g of sulphuric acid (H2SO4).
19. Determine the simplest formula of the compound given the percentage (by mass)
composition: 29.2% sodium, 40.5% sulfur, and 30.3% oxygen.
20. Aspirin contains 60.00% by mass carbon, 4.48% by mass hydrogen and the rest oxygen. If
aspirin has a molecular mass of 360, what is its molecular formula?
21. A sample of a liquid used in dry-cleaning was found to consist of 10.06% carbon, 89.10%
chlorine, with the remainder being hydrogen. The molar mass of the compound was
determined to be 119.6 g. What is the molecular formula of the compound?
22. An organic compound having a molecular mass of 90 contains 40.00% of carbon, 6.71% of
hydrogen and the rest oxygen. Determine the molecular formula of the compound.
23. A compound containing boron, nitrogen, and hydrogen is found to be 40.3% boron, 52.2%
nitrogen and 7.5% hydrogen. Determine the simplest formula of the compound.
24. 54.0 g of aluminum react with sulphur to produce 150.3 g of aluminum sulphide. Use this
data to determine the empirical formula of aluminum sulphide.
25. A chloride of phosphorus contains 22.5% by mass phosphorus. Determine the empirical
formula of the compound.
26. When 65.4 g of zinc is combined with 80.0 g of chlorine, all of the zinc reacts and 9.0 g of the
chlorine is left unreacted. Name the compound formed and give the proper formula.
27. An organic compound has a simplest formula of CH2O and a molar mass of 180 g/mol.
Its molecular formula is
28. What is the molar mass of Ca(NO3)2?
29. Determine the molar mass of Mg3(PO4)2.
30. Determine the molar mass of Ca3(PO4)2.
31. What is the molar mass of a compound if 0.825 mol of the compound has a mass of 34.80 g?
32. Calculate the percentage of water in copper (II) sulphate pentahydrate, CuSO 4.5 H2O.
33. What is the percentage composition of hydrogen in CH 3OH?
34. What is the percentage composition of nitrogen in Cu(NO3)2?
35. Calculate the percentage (by mass) of aluminum in Al2O3.
36. Determine the formula of the hydrate of magnesium sulphate (MgSO 4. x H2O) given that
4.930 g of the hydrate produces 2.408 g of anhydrous magnesium sulphate.
37. Determine the formula of the hydrate of MgSO4.x H2O given that 2.465 g of the hydrate
produces 1.204 g of anhydrous MgSO4.
38. Determine the number of water molecules (x) attached to each molecule of barium
hydroxide in the hydrated compound Ba(OH)2.xH20, given that heating 30.4 g of the hydrate
produces 13.9 g of water.
39. When 9.416 g of a hydrate of cobalt thiocyanate Co(SCN) 2.xH2O were heated, 7.197 g of the
anhydrous solid remained. Calculate the number of water molecules in the formula of the
hydrated salt.
40. Exactly one gram of cobalt chloride hydrate, CoCl2.xH2O was heated to drive off water. The
mass of the residue was 0.547 g. Find the value of x in the formula.