Predict the chemical formulas of the compounds formed by the following pairs of ions: (e) NH4+ and PO43-
Alright guys, so here we have to predict the chemical formula. So we have ammonium and we have phosphate. So let's take a look at the charges. So ammonium has a charge of +1 and phosphate has a charge of -3. Are the numbers the same or different? They're going to be different because ammonium is 1 and phosphate is 3. So since they're different that means that they will criss-cross.
So the 3 from phosphate is going to come to ammonium and the 1 from ammonium will go to the phosphate so the chemical formula is going to be NH43PO4 and since we're dealing with polyatomic ions, we're going to have to place the parenthesis there to show that the 3 that came from the phosphate belongs to all the atoms that are present in the compound. So make sure you don't forget your parenthesis because if you don't put the parenthesis it will be a wrong answer.