How to determine whether an object is more or less electronegative than another

[ctamasi]

I'm doing a lab on electrostatics, and I need to develop an electrostatic series.

I've established a small sheet of plastic (20") as my reference material for determining charges.

In my lab, it was given, that rubbing plastic in wool would give the plastic a negative charge meaning it is more electronegative than wool. So, so far my series looks like this:

Wool
Plastic

(more electropositive substances at the top - more electronengative substances at the bottom)

Then I rubbed a balloon in wool and moved it close to the reference material, plastic, and they repelled. This obviously shows that they have like charges. Therefore, the balloon has a negative charge like that plastic which makes it more electronegative than the wool. But now how do I determine which substance is more electronegative of the two, the balloon or the plastic? So the series is something like this now,

Wool
Plastic - Balloon

I'm not sure how to order the plastic and the balloon, all I know is that they are both more electronegative than wool.

Is there any way of determining this?

thanks a lot.

 

[jbsteele]

Yes, there is a way to determine the relative electronegativity of the plastic and the balloon. To do this, you will need to measure the strength of the electrostatic force between the plastic and the balloon. If the force is strong, then the two materials have a similar charge, meaning that they are both equally electronegative. If the force is weak, then one material has a more negative charge than the other, and thus is more electronegative.

 

[tomcue]

To determine which substance is more electronegative, we can use a concept called the "electron affinity." This refers to the tendency of an atom to attract electrons towards itself. The higher the electron affinity, the more electronegative the substance is.

In your lab, you can measure the electron affinity of the plastic and the balloon by using a device called an electroscope. An electroscope can detect the presence and direction of electric charges, and it can also measure the strength of the charge.

First, charge the electroscope by rubbing it with a wool cloth. Then, bring the electroscope close to the plastic and record the deflection of the electroscope. Next, bring the electroscope close to the balloon and record the deflection again. The substance that causes a greater deflection of the electroscope is more electronegative.

Another method is to compare the ionization energies of the two substances. Ionization energy is the amount of energy required to remove an electron from an atom or molecule. The higher the ionization energy, the more electronegative the substance is. You can look up the ionization energies of plastic and the balloon and compare them to determine which one is more electronegative.

In summary, to determine which substance is more electronegative, you can use either the electron affinity or the ionization energy. Both methods can provide quantitative data to rank the substances in your electrostatic series.