Page 210 - Chemistry eBook

Writing Binary Compound Formulas
1. Write the symbols of both elements.
2. Assign oxidation numbers.
3. Use the crisscross method: Swap the oxidation numbers of the two atoms in
crisscross fashion, moving the number from the top right of one symbol to the
bottom right of the other symbol. Leave out the positive or negative signs.
4. Simplify/reduce if possible.
C6H12 can be simplified by dividing both subscripts by 6. Answer: CH2.
Look up the oxidation numbers on
Reffy’s periodic table.
Find the formula of Boron oxide.
1. Write the symbols of both elements.
BO
2. The oxidation state of B is +3. O’s
is -2. We would write: B+3O-2
3. Crisscross:
4. It’s already in simplest form, so we don’t need to reduce.
209 © UNIT 6: MATH IN CHEMISTRY