How do I work out the chemical formulas for:
~Potassium Chloride
~Magnesium Sulphate
~Sodium Hydronide
~Silver Oxide
~Barium Chloride
~Aluminum Oxide
~Ammonium Nitrate
~Copper Sulphate
~Calcium Phosphate
~Hydrogen Phosphate
Tags: Chemical, For...., Formulas, Work
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To “work them out” you need to know the usual charges of the various cations and anions.
For magnesium sulfate, you know (hopefully) Mg’s only common oxidation state is Mg+2; the charge on SO4 is -2 (you can think of it as S+6 and 4 (O-2) = SO4-2).
Since the charges are equal and opposite the ratio is one to one or MgSO4
For calcium phospate Ca is a +2 ion; phospate is a -3 ion (you can think of it as P+5 and 4 O-2 = PO4-3). Since the two charges are not equal, you need to adjust the ratio of the cation/anion to achieve a neutral compound. You can see that 3 (+2 ions) = +6, and 2 (-3 ions) = -6 so the formula is Ca3(PO4)2 all the others can be done similarly.
Eventually, these charges and ratios of cations & anions will be so drilled into your brain you will be able to solve them instantly just by looking at them.
KCl
MgSO4
NaOH
Ag2O
BaCl2
Al2O3
NH4NO3
CuSO4
Ca3(PO4)2
H3PO4