<u>Answer:</u> The mole ratio of H : O in ammonium nitrate is 4 : 3.
<u>Explanation:</u>
We are given a compound named ammonium nitrate having formula 
There are 3 elements in this compound which are nitrogen, hydrogen and oxygen.
To calculate the mole ratio, we write the ratio of their subscripts. For this compound, it is:

The mole ratio of H and O for this compound is 4 : 3.
The formula of the ppt. formed is PbSo4 , which is inslouble.
Neutralization reaction is the reaction between acid and base.
There the neutralization reaction is:
HBr + LiOH ----------> LiBr + H2O.
Hope this helps!
Answer:
Sodium fluoride (NaF) does indeed follow the octet rule without any violations.