Use the periodic table of the elements to determine the percent ionic character of the bond in each of the following compounds

Question

1) LiCl
2) NO2
3) HCl
4) AlBr3
5) BeO

Answer 1

Rachel,

Pauling's equation is different from the one given by J.R.S. as follows:

% ionic character = [1-e^{-(ΔEN/2)^2}]x100%    (ΔEN is the |a-b|)

This means in the previous answer, the squaring of the exponent of e is missing. (Don't forget that the negative value of that exponent is used!)

There are actually several equations used for this calculation which give very similar answers, so your computer program may be using a different equation with slightly different answers.

I hope this helps.

Answer 2

The main ionic compounds are LiCl and AlBr3. The others are covalent (2 non metals). HCl is also covalent. Now to determine % ionic character you should look at the electro negativity values or more appropriatelay the differenc in EN betweven the element. The delta EN between Li and Cl is greater than the delta EN between Al an Br. This should give you a hint as to which has the greatest ionic character. To rank them all, you can calculate the % ionic character from

%ionic=[1-e^(-1/4)(a-b)]100
where
e is base of natural log
a-b is difference in electronegativity values of the 2 atoms