Examkrackers - Chemsitry - 1st 30 minute exam - question 14

[ibeatupnerds]

question asks: Hydrogen has a paouling electronegativity of 2.1. What is the value of delta sign (i don't know how to add the symbol on here) for hydrogen?
answer is 0.
explanation says: if you substitute H for X in the equation for delta sign in the passage, you can only arrive at zero.

i dont get it...

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[dreamer67]

yea, im not getting this question either...

 

[movax]

Passages defines the delta as the difference between H-X actual and H-X expected.

If you're talking about hydrogen itself (i.e. Element X is H), well then you end up with H-H, which is of course is going to be 0. The Pauling electronegativity they give you is superfluous information. They ask for the delta, it's provided in the equation, and you should see that if you're talking about hydrogen itself, the delta is going to be zero.

 

[BoneMental]

Passages defines the delta as the difference between H-X actual and H-X expected.

If you're talking about hydrogen itself (i.e. Element X is H), well then you end up with H-H, which is of course is going to be 0. The Pauling electronegativity they give you is superfluous information. They ask for the delta, it's provided in the equation, and you should see that if you're talking about hydrogen itself, the delta is going to be zero.

True.

 

[LeonVCU]

I still don't get it . If hydrogen has some kind of electronegativity then why should H-H(actual bond) - H-H(expected bond) be zero? How do you know what is "expected" and what is "actual"?

 

[LeonVCU]

oh wait a minute, I've just noticed the bottom equation I get it now