Question

Tell me which names are incorrect and why

Look at the following formulas and corresponding names and tell me which names are incorrect and why.

CaCl2 Calcium chloride

Cu2O Copper (II) oxide

PbS2 Lead (II) sulfide

Answer 1

pbs2 lead [IV] sulfide is a chemical compound / Cu2o Copper [I] Oxide

Answer 2

Step-by-step explanation:

The nomenclature of ionic compounds is given by:

1. Positive is written first. And if the metal atom has various oxidation states then its oxidation state is to be mentioned in brackets with help of roman numbers

2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.

1.)
`CaCl_2` : Calcium chloride (Correct)

In the given compound, calcium has oxidation state of +2 and chlorine has oxidation state of -1.The name is correct.

2.)
`Cu_2O` : Copper (II) oxide (Incorrect)

In the given compound,copper has the oxidation state of +1 and oxygen has oxidation state of -2.So ,the correct name will be Copper (I) oxide.

3.)
`PbS_2` : Lead (II) sulfide (Incorrect)

In the given compound, lead has the oxidation state of +4 and sulfur has oxidation state of -2. So ,the correct name will be Lead (IV) sulfide.