What is the formula for titanium(III) oxide?

Question

Olivia Anton · Accepted Answer

#"Ti"_2"O"_3#

An ionic compound's name consists of the names of the anion, or negatively charged ion, at the end and the cation, or positively charged ion, at the beginning.

A Roman numeral is now added to the name of a transition metal to indicate its charge in the compound when it forms the cation.

The cation in question is called

titanium III

This means that you're dealing with a cation of titanium, #"Ti"#, that carries a #color(red)(3+)# charge, hence the (III) Roman numeral used in its name.

The anion goes by the name of

oxide

As you know, oxygen, #"O"#, is located in group 16, which means that it accepts two electrons to complete its octet. This tells you that the oxide anion will carry a #color(blue)(2-)# charge.

Now, an ionic compound needs to be electrically neutral. A titanium(III) oxide formula unit has to contain the following in order to balance the total positive charge from the cation with the total negative charge from the anion:

#color(blue)(2) xx "Ti"^(color(red)(3+))" "# and #" "color(red)(3) xx "O"^color(blue)(2-)#

Thus, titanium(III) oxide's chemical formula can be expressed as

#2 xx ["Ti"^(3+)] + 3 xx ["O"^(2-)] = color(green)(|bar(ul(color(white)(a/a)color(black)("Ti"_2"O"_3)color(white)(a/a)|)))#

Owen Ambrose · Answer

undefined Ti2O3 is the formula for titanium(III) oxide.