Question

Part A SeO3 Spell out the full name of the compound.

Answer 1

Answer : Selenium trioxide

Se is short name of Selenium and O is the short name for Oxygen

for 1 atom of an element use prefix mono,

2 atoms of same element we use prefix di,

3 atoms of same element we use prefix tri,

4 atoms of same element we use prefix tetra

5 atoms of same element we use prefix penta

6 atoms of same element we use prefix hexa

7 atoms of same element we use prefix hepta

8 atoms of same element we use prefix octa

9 atoms of same element we use prefix non

10 atomsof same element we use prefix deca

And for non-metal atoms use suffix -ide

Here, 1 Selenium and 3 oxygen atoms are there . so name will be mono Selenium tri Oxygen- ide. But according to IUPAC naming convention prefix should not be there for first atom so mono for Selenium and space should be there for prefix and name of the atom and suffix replace some letters so, trioxide rather than tri oxygen ide

Therefore, name of the compound is Selenium trioxide

Similarly, CO2 name is carbon dioxide

PCl5 : Phosphorous pentachloride