Names & Formulae of Ionic Compounds Flashcards

All 5 cards in this deck

What does the ending –ate tell you about a compound's name?

It contains the named elements plus oxygen.

e.g. sodium sulfate contains sodium, sulfur and oxygen

What are the steps to deduce the formula of an ionic compound from its ions?

e.g. $\mathrm{Ti^{4+}}$ and $\mathrm{SO_4^{2-}}$

1. Write the charges: 4+ and 2−
2. Choose numbers of each ion so the total charge is zero: one $\mathrm{Ti^{4+}}$, two $\mathrm{SO_4^{2-}}$
3. Write as subscripts, brackets round a group ion taken more than once: $\mathrm{Ti(SO_4)_2}$

Give the formulae and charges of the hydroxide, nitrate, carbonate and sulfate ions.

$\mathrm{OH^-}$, $\mathrm{NO_3^-}$, $\mathrm{CO_3^{2-}}$, $\mathrm{SO_4^{2-}}$

True or false? The charges must be written in the final formula of an ionic compound.

False. The formula is written without charges, e.g. $\mathrm{Na_2SO_4}$, and the numbers must be subscripts.

What does the ending –ide tell you about a compound's name?

The compound contains only the elements named, with no extra oxygen. Hydroxide is the exception: it contains oxygen and hydrogen.

e.g. potassium bromide contains only potassium and bromine