What is the charge of sulfate (SO4)?

The sulfate ion (SO4) carries a charge of -2. This can be understood by examining the composition of the sulfate ion. It is made up of one sulfur atom and four oxygen atoms. In terms of electronegativity, oxygen is more electronegative than sulfur, which results in the oxygen atoms pulling electron density away from sulfur, leading to an overall negative charge.

Each oxygen atom typically has a charge of -2, and since there are four oxygen atoms, the total charge contributed by the oxygen is -8. However, the sulfur atom has a charge of +6 in its most common oxidation state when combined with oxygen atoms. This can be accepted based on the bonding in the sulfate ion, where sulfur shares its electrons with the four oxygen atoms to fulfill their bonding requirements.

To find the net charge, you can sum these contributions: +6 (from sulfur) + (-8) (from the four oxygen atoms) = -2. Therefore, the sulfate ion is overall -2, making this the correct charge for sulfate.