EXERCISES I
In each of the following balancing exercises, you will first need
to use the calculator below and click on the UNDO button until the
formula entry window is clear. You will then enter a # sign followed
by the alphabetic character specified and a ? mark and hit SUBMIT. The required
equation should appear.
Remember, to insert a coefficient in front of
a chemical, click on the formula window and move the blinking cursor
directly in front of the desired chemical. Then type the coefficient
and click on the SUBMIT button when done.
1. Enter the equation:
Fe + O2 => Fe2O3 by typing #L? and hitting SUBMIT.
Since each element occurs only once on each side, this is easy to balance
You could use fractions but it is recommended you cross multiply to
balance O on each side. You then only need to choose a coefficient for Fe.
2. Enter the equation:
KClO3 => KCl + O2 by typing #K? and hitting SUBMIT.
You have balanced this before as your first real equation but this time
try it using fractions. You must determine
what fraction to multiply O2 by to achieve a balance and then multiply the
entire equation by that fraction's denominator to integerize the solution.
3. Enter the equation:
HgO => Hg + O2 by typing #B? and hitting SUBMIT
You may cross multiply or use fractions to balance this one.
Note that if you cross multiply O, O2 simply gets multiplied by 1.
4. Enter the equation:
Fe + HCl => FeCl2 + H2 by typing #D? and hitting SUBMIT
This one should be easy for you. Choose the coefficient for Fe
on the left side last. We do this because it occurs by itself. Elements
that occur by themselves as easy to bring into balance on the last
few steps.
5. Enter the equation:
Al + H2SO4 => Al2(SO4)3 + H2 by typing #Q? and hitting SUBMIT
Note that Al occurs by itself on the left side and H occurs
by itself on the right side so we should choose their coefficients
on the last two steps. SO4 always occurs as a group so it can be treated
as if it were a single element. If we multiply H2SO4 by 3, SO4 will be
balanced on each side.
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