Chemistry Reference
In-Depth Information
4.
[soluble]—Compounds containing halogens tend to be soluble.
5.
[insoluble]—Here, you see an exception to the solubility of halogens.
6.
[soluble]—Hydroxides are bases.
Lesson 6-4 Review
1.
[reduction]—Although the substance is gaining electrons, its charge is being
reduced.
2.
[oxidizing]—It is also the substance that gets reduced.
3.
[oxidation]—The process of oxidation is no longer limited to processes
involving oxygen.
4.
[reducing]—The reducing agent gets oxidized by losing electrons.
5.
[3H
2
0
+ N
2
0
2N
3+
H
3
1-
—Nitrogen is being oxidized, and it is also the
reducing agent. Hydrogen is being reduced, and it is also the oxidizing agent.]
6.
[Fe
2
3+
O
3
2-
+ 3C
2+
O
2-
2Fe
0
+ 3C
4+
O
2
2-
—Iron is being reduced, and it is also
the oxidizing agent. Carbon is being oxidized, so it is also the reducing agent.]
7.
[Zn
0
+ H
2
1+
S
6+
O
4
2-
Zn
2+
S
6+
O
4
2-
+ H
2
0
—Hydrogen is being reduced, so it is
also the oxidizing agent. Zinc is being oxidized, so it is also the reducing agent.]
8.
[2Mg
0
+ O
2
0
2Mg
2+
O
2-
—Oxygen is being reduced, so it is also the
oxidizing agent. Magnesium is being oxidized, and it is also the reducing
agent.]
Lesson 6-5 Review
1.
8
4
Be +
4
2
He
12
6
C
[ ]—The mass number on the right side of the equation
was 4 greater than the mass shown on the left side, so we know the mass
number of the unknown is 4 (12 - 8 = 4). We know that the atomic number
of X has to be 2 (6 - 4 = 2), in order for the atomic number to be balanced
on both sides of the equation. The element with an atomic number of 2 is
helium.
12
6
C +
4
2
He
16
8
O
2.
[ ]—The left hand side of the equation was showing a
total mass of 16 (12 + 4 = 16). The total of the atomic numbers on the left
side of the equation was 8 (6 + 2 = 8). This gave us an unknown with an
atomic number of 8, which could only be oxygen.
37
18
Ar +
0
-1
e
37
17
Cl
3.
[ ]—This was an interesting example. The mass number
was already balanced, so X must have a mass of 0 (37 - 37 = 0). The atomic
number on the left was already greater than the atomic number on the
right, so we had to add a negative number to the atomic number in order to
balance the nuclear charge, because 18 + (-1) = 17. X, with a mass of 0 and
a charge of -1, could only be an electron.
