Question

What are the components of one formula unit of caf2.

Answer 1

A calcium fluoride (
`{\rm CaF_(2)`) formula unit includes one calcium ion and two fluoride ions.

Step-by-step explanation:

The content of one formula unit of an ionic compound is exactly the same as what its empirical formula would suggest. (The empirical formula shows the atoms that form this compound, in the smallest whole number ratio.)

For example,
`{\rm CaF_(2)}` is the empirical formula of the ionic compound calcium fluoride. One formula unit of this compound would thus include:

• a calcium atom, and
• two fluoride ions.

However, since
`{\rm CaF_(2)}\!` is an ionic compound, all these atoms would take the form of ions:

• 
  `{\rm Ca^(2+)}` (calcium ion) for calcium, and
• 
  `{\rm F^(-)}` (fluoride ion) for fluorine.

Thus, one formula unit of
`{\rm CaF_(2)}` would include
`1` calcium ion and
`2` fluoride ions.