• Best of luck to the class of 2024 for their HSC exams. You got this!
    Let us know your thoughts on the HSC exams here
  • YOU can help the next generation of students in the community!
    Share your trial papers and notes on our Notes & Resources page
MedVision ad

Simple Chem. Question (1 Viewer)

McRafi9

New Member
Joined
Nov 14, 2016
Messages
14
Gender
Male
HSC
2018
Please provide explanation along with the solution.

In which compound is the valency of lead NOT 2?

(A) PbO2

(B) PbSO4

(C) PbCl2

(D) Pb(OH)2
 

jazz519

Moderator
Moderator
Joined
Feb 25, 2015
Messages
1,955
Location
Sydney
Gender
Male
HSC
2016
Uni Grad
2021
Please provide explanation along with the solution.

In which compound is the valency of lead NOT 2?

(A) PbO2

(B) PbSO4

(C) PbCl2

(D) Pb(OH)2
For this question you have to use the oxidation state rules. So we know that a compound has an overall oxidation state of 0, while oxygen is -2 (unless in peroxide where it's -1 but none of these compounds are peroxides).

So for (a) there is two oxygens so the o2 is 4- but the overall compound has a 0 oxidation state so the lead must be 4+ (Answer is A)

(B) sulphate ion is 2- so lead is 2+

(C) one cl ion is 1- so two cl ions is 2-, thus lead is 2+ Since the overall charges added up need to equal 0 since it's a compound

(D) one oh ion is 1- so two oh ions is 2- so lead is 2+
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top