We’ll go over this example in video form.
Name the compound with the formula Au(NO3)3
We’re asked to name the compound with the formula Au, NO3 in brackets, 3.
Name the compound with the formula Au(NO3)3
Au(NO3)3
3 Elements
We see that Au(NO3)3 has 3 elements (click) gold, nitrogen, and oxygen. Any ionic
compound with more than two elements must contain a polyatomic ion.
Name the compound with the formula Au(NO3)3
Au(NO3)3
So we look for polyatomic ions in the formula Au(NO3)3
Name the compound with the formula Au(NO3)3
Au(NO3)3
NO3 comes from (click) the nitrate ion, NO3 minus.
Name the compound with the formula Au(NO3)3
Au(NO3)3
Gold is a singe metal but its not on the Positive Ion section of the table
here.
Name the compound with the formula Au(NO3)3
Au(NO3)3
But it is found here, quite low in the middle section of the periodic table
Name the compound with the formula Au(NO3)3
gold(III) nitrate
3+
Au
+4
–
NO3
–
NO3
–
NO–4
3
We can start writing the name: the metal is (click) gold, and the
polyatomic ion is (click) nitrate
Name the compound with the formula Au(NO3)3
gold(III) nitrate
3+
Au
roman
numeral
+4
–
NO3
–
NO3
–
NO–4
3
Because gold has more than one possible charge we have to indicate the
charge (click) with a roman numeral
Name the compound with the formula Au(NO3)3
? nitrate
gold(III)
?
?
3+
Au
roman
numeral
+4
–
NO3
–
NO3
–
NO–4
3
Is the charge positive 3 or positive 1 and (click) what is the roman numeral? Here’s
how we find the charge on gold…
Name the compound with the formula Au(NO3)3
3+
Au
+4
–
NO3
–
NO3
–
NO–4
3
The formula tells us we have one gold ion
Name the compound with the formula Au(NO3)3
3+
Au
+4
And 3 nitrate ions.
–
NO3
–
NO3
–
NO–4
3
Name the compound with the formula Au(NO3)3
3+
Au
Total
Positive
Charge
+4
+3
–
NO3
–
NO3
–
NO–4
3
–3
Total
Negativ
e
Charge
Each nitrate ion has a charge of negative 1, so the total negative charge is
3 times negative 1, (click) which is negative 3
Name the compound with the formula Au(NO3)3
3+
Au
Total
Positive
Charge
+4
+3
–
NO3
–
NO3
–
NO–4
3
–3
The positive and negative charges (click) must be balanced.
Total
Negativ
e
Charge
Name the compound with the formula Au(NO3)3
3+
Au
Total
Positive
Charge
+4
+3
–
NO3
–
NO3
–
NO–4
3
–3
Total
Negativ
e
Charge
So the total positive charge must be positive 3. There is only one gold ion,
Name the compound with the formula Au(NO3)3
3+
Au
Total
Positive
Charge
+4
+3
–
NO3
–
NO3
–
NO–4
3
–3
So the charge on this gold ion (click) must be positive 3
Total
Negativ
e
Charge
Name the compound with the formula Au(NO3)3
? nitrate
gold(III)
3+
Au
Total
Positive
Charge
+4
+3
–
NO3
–
NO3
–
NO–4
3
–3
Total
Negativ
e
Charge
The roman numeral represents the charge on one gold ion, so (click) the
roman numeral is, (click)
Name the compound with the formula Au(NO3)3
gold(III) nitrate
3+
Au
Total
Positive
Charge
3
+4
+3
–
NO3
–
NO3
–
NO–4
3
–3
Total
Negativ
e
Charge
Name the compound with the formula Au(NO3)3
gold(III) nitrate
3+
Au
Total
Positive
Charge
+4
+3
Name
–
NO3
–
NO3
–
NO–4
3
So the name of this compound is gold (III) nitrate.
–3
Total
Negativ
e
Charge
Name the compound with the formula Au(NO3)3
gold(III) nitrate
So the final answer is (click) the name of this compound is gold (III)
nitrate.