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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: butterwings on October 06, 2009, 10:01:29 AM

Title: Octet rule
Post by: butterwings on October 06, 2009, 10:01:29 AM
Which of the following compounds present exceptions to the octet rule ?

a) PF5

b) XeF4O

c) SCl2

d) ClF3

e) NF3

ATTEMPT
I know that it is not a and d so i wen down with bce. I draw it out and then they seem correct.

but then wen i put in the answer, i got it incorrect.

i also tried b, bc, bce, e, and abce. and they are all wrong. I am confuse and i need help. thank you.
Title: Re: Octet rule
Post by: DrCMS on October 06, 2009, 10:14:04 AM
What is the octet rule?

How many electrons does P have in unfilled shells?
How many electron does F have in unfilled shells?

In PF5 if each P-F bond has 1 electron from each atoms does P meet the octet rule?

Now try the others.
Title: Re: Octet rule
Post by: butterwings on October 06, 2009, 10:30:33 AM
The octet rule is a simple chemical rule of thumb that states that atoms tend to combine in such a way that they each have eight electrons in their valence shells, giving them the same electronic configuration as a noble gas.

PF5 Does NOT follow the octet rule since P has 5 valence pair around it. No for ClF3 since it have 5 valence pair too.

and then i'm stuck. but so far, am i correct? thank you so much for helping. i still need more help though. thanks!
Title: Re: Octet rule
Post by: DrCMS on October 06, 2009, 10:48:34 AM
So far so good PF5 and ClF3 do not follow the octet rule.

What about NF3 and SCl2 do they follow it or not?