2007-02-20 16:18:56 · 3 answers · asked by Sara G 1 in Science & Mathematics ➔ Chemistry
Zn 2+ and PO4 3- do not balance the charges as they are written. You need 3 time the Zn 2+ and 2 times the PO4 3- to make a molecule that has equal numbers of + and - charges.
If we were to write the formula as:
Zn3PO42 the subscript "2" after the PO4 appears to mean "42" oxygen. That is not what we meant.
By using parentheses around any polyatomic ion we mean to use that many of the entire ion. Just like in math:
3(x + 2) means to take 3 times x and 3 times 2 to get 3x + 6.
The subscript after the parentheses means to take two times the PO4 ion.
Zn3(PO4)2
2007-02-20 16:24:04 · answer #1 · answered by physandchemteach 7 · 0⤊ 0⤋
It isn't. It is conventional to write Zn3(PO4)2, but Zn3P2O8 is also valid.
2007-02-20 16:26:38 · answer #2 · answered by Anonymous · 0⤊ 0⤋
so "not so smart" people like the teachers won't be confused.
2007-02-20 16:26:16 · answer #3 · answered by Scpwnz 5 · 0⤊ 0⤋