Week 4.docx - Written Assignment 4 Chemical Reactions...

Written Assignment 4: Chemical Reactions
Answer all assigned questions and problems, and show all work.
1. Write the (a) balanced equation for the formation of liquid water from hydrogen and
oxygen gas, and use it to explain the following terms: (b) chemical reaction, (c)
reactant, (d) product. (12 points)
 2H2+O2=2H2o
 Chemical reaction – process in which a substance is changed into one or more
new substances
 Reactant- The starting material in a chemical reaction
 Product- What is produced as a result of the chemical reaction
2. Balance the following equations: (18 points)
a. C + O
2
→ CO
 2C+02=2CO
b. CO + O
2
→ CO
2
 2CO+O2=2CO2
c. Na + H
2
O → H
2
+ NaOH
 2Na+2H20=H2+2NaOH
d. Zn + HCl → ZnCl
2
+ H
2
 Zn+2HCl=ZnCl2+H2
e. NaOH + H
2
SO
4
→ H
2
O + Na
2
SO
4
 2NaOH + H
2
SO
4
= 2H
2
O + Na
2
SO
4
f. NH
3
+ CuO → Cu + N
2
+ H
2
O
 2NH
3
+ 3CuO = 3Cu + N
2
+ 3H
2
O
3. Calculate the mass in grams of iodine (I
2
) that will react completely with 20.4 g of
aluminum (Al) to form aluminum iodide (AlI
3
). (5 points)
 2Al+3I2=2AlI3
 1 mole of Al is 27 grams
 20.4/27=.75 moles
 .75*(3/2)=1.13 moles of I
 1 mole of I2= 254
1
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 1.13*254 = 287 grams
(Reference: Chang 3.47)
4. The annual production of sulfur dioxide from burning coal and fossil fuels, auto
exhaust, and other sources is about 26 million tons. The equation for the reaction is