Chemistry Reference
In-Depth Information
5.
[2HCl + Ca(OH)
2
CaCl
2
+ 2H
2
O]—The atomic tally showed that we only
had 3 hydrogen on the reactant side, and 4 on the product side. By adding a
coefficient of 2 to the hydrogen chloride, the entire equation balanced out.
6.
[2C
2
H
6
+ 7O
2
4CO
2
+ 6H
2
O]—We can only have an even number of
oxygen on the reactant side, so we needed to put an even-numbered
coefficient in front of the water, or we would have an odd number of oxygen
on the product side.
7.
[4Fe + 3O
2
2Fe
2
O
3
]—Again, we needed to put an even-numbered
coefficient on the product side, just to get an even number of oxygen there.
8.
[2Na + 2H
2
O
2NaOH + H
2
]—This time, I knew that I needed to add an
even-numbered coefficient to the sodium hydroxide (NaOH) in order to
have an even number of hydrogen on the product side. After that, the rest
falls into place.
Lesson 6-2 Review
1. [decomposition]—This reaction shows a more complex substance breaking
down into two simpler substances.
2. [synthesis]—Here we see two simpler substances combining into a more
complex substance.
3. [single replacement]—The chlorine replaces the bromine; think of it as if
someone “cutting in” on a dancing couple.
4. [single replacement]—Here we see zinc replacing hydrogen.
5. [combustion]—When a hydrocarbon reacts with oxygen to form water and
carbon dioxide, we call it combustion.
6. [double replacement]—The ions seem to switch partners, as the lead and
potassium replace each other.
7. [synthesis]—The two elements, silver and chlorine, combine to form a
compound.
8. [double replacement]—The hydrogen and iron switch places. When the
hydrogen combines with oxygen, it forms water.
9. [decomposition]—The magnesium carbonate is breaking down into simpler
substances.
10. [combustion]—Notice that the products are water and carbon dioxide.
Lesson 6-3 Review
1.
[soluble]—Simply cross-reference the ions in the solubility rules.
2.
[soluble]—Compounds containing halogens tend to be soluble.
3.
[insoluble]—If a reaction forms zinc carbonate, it will precipitate out.
