What is the name of #Pb_3P_2#?

1 Answer
Oct 12, 2016

Answer:

Lead #(II)# phosphide

Explanation:

#Pb=#lead
#P=#phosphorus#->#the phosphorus anion is phosphide (#P^(3-)#)

  • It is important to note that this is phosphide, not phosphate, as the anion does not have oxygen attached
  • Phosphate#=PO_4^(3-)#

If you are not sure about the oxidation state of lead, add up the oxidation state of the phosphide #P^(3-)# ions and see what is needed to cancel it out to make it neutral (as this is a compound with a neutral charge).

  • Oxidation state of #P^(3-)# is #-III#, since it has gained 3 electrons
  • There are 2 #P^(3-)# in the compound, so #2*-III=-VI#
  • To cancel out #-VI#, we need #+VI#
  • There are 3 lead ions, so #(VI)/3=II#