Download Chemical Practice

Name ____________________________________
Date ____________________ Hour _________
Chemical Practice
Examples:
Oxidation numbers need to be balanced / canceled out!
1. If an element has +3 oxidation #, it has __ valence electrons and wants to (lose/gain) __ electrons.
+2 oxidation means there is __ valence electrons and wants to (lose/gain) __ electrons.
- 2 oxidation means there is __ valence electrons and wants to (lose/gain) __ electrons.
- 1 oxidation means there is __ valence electrons and wants to (lose/gain) __ electrons.
+1 oxidation means there is __ valence electrons and wants to (lose/gain) __ electrons.
The noble gasses have _ _ valence electrons and want to (lose/gain) __ electrons.
2. What is ionic bonding?
3. What is the definition of an oxidation number?
4. If an element has an oxidation number of +2, what will it want to do?
5. Hydrogen cannot combine with Neon to form a compound. Why?
6. Calcium and Potassium cannot combine to form a compound. Why?
7. In order for an ionic bond to happen, a ______ ion must mix with a ______ ion.
8. If an element loses three electrons, what is its new charge?
9. How can you explain why the elements in Carbon’s family have either +4 or – 4 oxidation number?
10. To balance out the oxidation #’s for a +1 and -2 bond, there needs to be 2 (+1) for every 1 (-2).
To balance out the oxidation #’s for a +3 and -3 bond, there needs to be __ (+3) for every __ (-3).
To balance out the oxidation #’s for a +2 and -1 bond, there needs to be __ (+2) for every __ (-1).
To balance out the oxidation #’s for a +1 and -4 bond, there needs to be __ (+1) for every __ (-4).
To balance out the oxidation #’s for a +2 and -3 bond, there needs to be __ (+2) for every __ (-3).
To balance out the oxidation #’s for a +3 and -2 bond, there needs to be __ (+3) for every __ (-2).
11. What will happen if you mix some of an element that wants to gain three electrons with some that wants
to lose one electron? [Hint: consider the ions each would form.]
12. What will happen if you mix together a bunch of two different elements, one with an oxidation of +2
and one with the oxidation of – 1? [Hint: the oxidation numbers need to cancel out.]
13. What will happen if you mix +2 ions with – 3 ions? [Hint: the oxidations need to cancel out.]
2
14. Write in the Oxidation numbers of the elements on the left column and the top row on the table below.
Then, write the formula of the combination of ions on the left column and the top row. Study the ones
done for you.
P ____
S ____
F ____
Li3P
Li ____
BeS
Be ____
Al ____
Cu +1
CuF
Cu +2
CuF2
Fe +2
Fe +3
15. The metals in families 3 – 12 behave differently than the other families in terms of forming ions.
Copper (Cu) and Iron (Fe) are examples of these metals. The oxidation number of these metals will be
given to you. What is one simple observation you can make about one of these metal ions?
16. Take a guess…..why you think some metal ions might have two oxidation numbers?
17. What is a polyatomic ion?
Formulas and Naming Compounds
READ: Write the oxidation number for each ion (some are given). Write the formula for the ionic bond and
the name of this new compound. Always write the cation (+ ion) first in the formula.
Use the back of your periodic table to put the names of the two ions together. The names of the ions may be a
little different to show that it is now in a compound. The chlorine ion is called chloride, bromine is bromide,
sulfur is sulfide, oxygen is oxide….. If they will not combine, write NOT POSSIBLE.
Ion with oxidation
number
Ion with oxidation
number
Compound formula
Name of compound
Mg +2
Br –1
MgBr2
Magnesium bromide
H ___
Cl ___
Ca ___
Br ___
3
Ion with oxidation
number
Ion with oxidation
number
H ___
S ___
Na ___
Ar ___
Ca ___
Na ___
Fe +2
O ___
Fe +3
O ___
Cl ___
Be ___
Si ___
O ___
H ___
P ___
Xe ___
Mg ___
P ___
Al ___
Cu +2
Cl ___
Cu +1
Cl ___
He ___
F ___
Br ___
Al ___
NH4 ___
PO4 ___
NH4 ___
NO3 ___
SiO4 –4
K ___
B ___
OH ___
Compound formula
Name of compound
N/A
Not possible
(NH4)3PO4
Ammonium phosphate
Potassium silicate
Using the back of your periodic table, find the formulas for the following compounds containing polyatomic
ions. First write the formula for each ion which is being bonded.
Compound Name
Ions in Compound
Sodium Carbonate:
Na
Magnesium Sulfate:
____________________
_____________________
Potassium Nitrate:
____________________
_____________________
Aluminum Hydroxide:
____________________
_____________________
Ammonium Carbonate:
____________________
_____________________
Iron (III) Oxide:
____________________
_____________________
Sulfur Phosphate:
____________________
_____________________
Calcium Chlorite:
____________________
_____________________
Hydrogen Hydroxide:
____________________
4
_____________________ (H2O)
+1
CO3
–2
Compound Formula
___Na2CO3_
____