Description of Action |
Action |
1. Name the
cation. |
1. copper |
2. Check your
periodic table to see if the element has more than one charge. If
it does, write empty parenthesis after the cation’s name. |
2. Yes its has
charges of 1+ and 2+.
copper( )
|
3. Name the
anion. At the bottom of the parenthesis, write the possible charges.
Your Roman Numeral can only be one of these charges. |
3. copper( 1,2
) phosphite |
4. Look at your
formula. If they are not already written, put parenthesis around any
polyatomic ions. |
4. Cu3(PO3)
Phosphite is polyatomic, so I put parenthesis around it. Copper is
not polyatomic, so it does not need parenthesis. |
5. Write the
anion’s charge to the top right of its symbol, outside of the
parenthesis. |
5. Cu3(PO3)3- |
6.
Multiply the anion’s charge and the anion’s subscript.
If the anion is polyatomic, use the subscript outside of the parenthesis.
If there is no number written, we must assume it is one. |
6. For this
formula we would multiply 3- (charge) x 1 (subscript). 3 x 1 = 3 |
7. Divide the
result by the subscript of the cation. Again, if there is no number
written, assume the subscript is one. |
7. Our result
was (3) and the subscript of copper (the cation) is 3, so we would
divide: 3 ÷ 3 = 1
|
8. Your new
result is the Roman Numeral to put in parenthesis after the cation’s
name. Be sure to check your periodic table to verify that the number
you use is valid. |
8. copper(I)
phosphite |
9. Since copper(I)
is also known as cuprous, you can also write the common name. Either
is acceptable. |
9. cuprous phosphite |