Hi, Question- How to find the valency of compounds like PO4, CO3, NO2, NO3, SO4 and so on... (Requesting you to only solve by the simplest method at a very basicc but logical level) Thank You.

ICSE Class 9 Answered

Hi, Question- How to find the valency of compounds like PO4, CO3, NO2, NO3, SO4 and so on... (Requesting you to only solve by the simplest method at a very basicc but logical level) Thank You.

Asked by tdeshpande502 | 23 Jun, 2020, 07:25: PM

Expert Answer

Dear student,

There is not a single method to find valency for all species because elements have valence electrons and it form bonds according to that.

Logic is each element wants to complete octet or duplet so that it can be stable.

for elements, you can use periodic table to remember it easily.

For example group-1 eleements (Li, Na, K.....) need to release one electron to acheive stability because 1 electron is present in outermost or valence shell. So all of these elements will show +1 valency.

Group-2 element (Be,Mg, Ca..) will show +2 valeny.

So, by looking at periodic table you will get an idea that elements belongs to same group have same valancy (few exceptions are also there)

But now let's come to ions like Nitrate, Carbonate-

In this situation you can identify valency by understanding structure but it is not worthy ito draw structures all the time and chances of mistakes are also high. So you need to remeber these valencies.

for more information and understandig about this topic, please follow the given link-

https://images.topperlearning.com/topper/revisionnotes/3224_Topper_21_110_1_2_392_1102_Basics_of_Chemistry_up201806041743_1528114381_2557.pdf?v=0.0.1

Answered by Ravi | 25 Jun, 2020, 09:28: PM