Download Chemical Arithmetic WebQuest Worksheet

Chemical Arithmetic WebQuest Worksheet
Follow the WebQuest Process and answer the problems in each section.
Section A
1. Calculate the formula mass of each of the following substances.
a. sodium chloride (table salt)
NaCl
22.99 amu + 35.45 amu = 58.44 amu
b. iron (III) chloride (wastewater treatment chemical)
FeCl3
55.85 amu + 3(35.45 amu) = 162.20 amu
c. calcium carbonate (ingredient in antacids)
CaCO3
40.08 amu + 12.01 amu + 3(16.00 amu) = 100.09 amu
2. How many molecules are contained in 1.0 mole of CH4?
1.0 mole CH4
6.02 x 1023 molecules CH4
= 6.02 x 1023 molecules CH4
1.0 mole CH4
3. How many molecules are contained in 5.0 moles of CO2?
5.0 mole CO2
6.02 x 1023 molecules CO2
= 3.01 x 1024 molecules CO2
1.0 mole CO2
4. Calculate the molar mass of each of the following substances.
a. lithium carbonate (a drug used to treat bipolar disorder)
Li2CO3
2(6.98 g/mole) + 12.01 g/mole + 3(16.00 g/mole) = 73.89 g/mole
b. C13H21NO3 (albuterol, a drug used to treat asthma)
C13H21NO3
13(12.01 g/mole) + 21(1.01 g/mole) + 14.01 g/mole + 3(16.00 g/mole) = 239.35 g/mole
Section B
1. Ethyl chloride, a local anesthetic, has a chemical formula of C2H5Cl. How many moles
of carbon atoms, hydrogen atoms and chlorine atoms are present in a 2.3 mole sample of
ethyl chloride?
2.3 mole C2H5Cl
2 moles C atoms
= 4.6 moles C atoms
1 mole C2H5Cl
2.3 mole C2H5Cl
5 moles H atoms
= 12 moles H atoms
1 mole C2H5Cl
2.3 mole C2H5Cl
1 mole Cl atoms
= 2.3 moles Cl atoms
1 mole C2H5Cl
2. Calculate the number of grams contained in each of the following number of moles.
a. 0.500 mole of NaCl
58.44 g NaCl
0.500 mole NaCl
= 29.2 g NaCl
1 mole NaCl
b. 3.6 moles of C2H4
28.06 g C2H4
3.6 mole C2H4
= 1.0 x 102 g C2H4
1 mole C2H4
c. 0.820 moles of C6H8O6
0.820 mole C6H8O6
176.14 g C6H8O6
= 144 g C6H8O6
1 mole C6H8O6
3. How many moles are contained in each of the following?
a. 100. g CaCl2
100. g CaCl2
1 mole CaCl2
= 0.901 mole CaCl2
110.98 g CaCl2
b. 25.5 g H2O
25.5 g H2O
1 mole H2O
= 1.42 mole H2O
18.02 g H2O
c. 0.250 g C9H8O4
0.250 g C9H8O4
1 mole C9H8O4
= 1.39 x 10-3 mole C9H8O4
180.17 g C9H8O4
4. Determine the mass, in grams, of 7.50 x 1017 atoms of He.
7.50 x 1017 atoms He
1 mole He
= 4.98 x 10-6 mole He
6.02 x 1023 atoms He
Section C
1. Write a chemical equation when gaseous methane (CH4) is heated with gaseous
chlorine (Cl2) to produce liquid carbon tetrachloride (CCl4) and gaseous hydrogen
chloride (HCl).
CH4 + Cl2
CCl4 + HCl
2. Balance the chemical equation above.
CH4 + 4 Cl2
CCl4 + 4 HCl
3. Write a balanced equation for each reaction.
a. Fe + O2 Fe2O3
2 Fe + 3 O2
b. CH4 + Cl2
CH4 + 2 Cl2
2 Fe2O3
CH2Cl2 + HCl
2 CH2Cl2 + 2HCl
4. Write a balanced equation for the reaction of glucose (C6H12O6) with oxygen (O2) to
form carbon dioxide (CO2) and water (H2O).
C6H12O6 + 6 O2
6 CO2 + 6 H2O
Section D
1. Balance the following equation: N2(g) + O2(g)
N2 + O 2
NO(g)
2 NO
a. How many moles of NO are formed from 3.3 moles of N2?
3.3 mole N2
2 mole NO
= 6.6 mole NO
1 mole N2
b. How many moles of NO are formed from 0.50 moles of O2?
0.50 mole O2
2 mole NO
= 1.0 mole NO
1 mole O2
c. How many moles of O2 are needed to form 1.8 moles of NO?
1.8 mole NO
1 mole O2
= 0.9 mole O2
2 mole NO
d. How many moles of N2 are needed to completely react with 1.2 moles of O2?
1.2 mole O2
1 mole N2
= 1.2 mole N2
1 mole O2
2. Balance the following equation: Na(s) + H2O(l)
2 Na + 2 H2O
NaOH(aq) + H2(g)
2 NaOH + H2
a. How many grams of NaOH are formed from 3.0 moles of Na?
3.0 mole Na
2 mole NaOH
40.00 g NaOH
= 120 g NaOH
2 mole Na
1 mole NaOH
b. How many grams of H2 are formed from 0.30 mole of Na?
0.30 mole Na
1 mole H2
2.02 g H2
= 0.30 g H2
2 mole Na
1 mole H2
c. How many grams of H2O are needed to react completely with 0.20 mole Na?
0.20 mole Na
2 mole H2O
18.02 g H2O
= 3.6 g H2O
2 mole Na
1 mole H2O
3. Balance the following equation: Fe2O3(s) + CO(g)
Fe2O3 + 3 CO
Fe(s) + CO2(g)
2 Fe + 3 CO2
a. How many grams of Fe are formed from 10.0 g of Fe2O3?
10.0 g Fe2O3
1 mole Fe2O3
2 mole Fe
55.85 g Fe
1 mole Fe2O3
1 mole Fe
= 6.99 g Fe
159.70 g Fe2O3
b. How many grams of Fe2O3 are needed to react completely with 25.5 g of CO?
25.5 g CO
1 mole CO
1 mole Fe2O3
159.70 g Fe2O3
28.01 g CO
3 mole CO
1 mole Fe2O3
= 48.5 g Fe2O3