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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: IBM on July 23, 2019, 02:08:42 PM

Title: Why does N get positive charge on it in NH4+ ion?
Post by: IBM on July 23, 2019, 02:08:42 PM
Why does N get positive charge on it in NH4+ as I know that atom has fixed proton number, there is no change? N has 7 protons in the neutral state but when H+ comes to N and accepts two lone paired electrons of N, N becomes N to N+ why?
My question is if N has 7 protons fixed and no matter what reaction happens the number of protons does not change but why N got positive charge after the H+ receives two lone paired electrons of N? How H+ ion can combine to the protons of N and produce N+? I am confused. Explain it, please.
Title: Re: Why does N get positive charge on it in NH4+ ion?
Post by: Borek on July 23, 2019, 03:05:24 PM
You are mistaking charge of the whole entity (NH4+) with charge on the N atom. In NH4+ the latter doesn't make much sense, it is whole ion that matters, and its total charge depends on the number of protons (both in N and in four H) and number electrons from all sources.

Count protons, count electrons. What do you get?
Title: Re: Why does N get positive charge on it in NH4+ ion?
Post by: IBM on July 23, 2019, 09:24:34 PM
Quote from: Borek on July 23, 2019, 03:05:24 PM
You are mistaking charge of the whole entity (NH4+) with the charge on the N atom. In NH4+ the latter doesn't make much sense, it is the whole ion that matters, and its total charge depends on the number of protons (both in N and in four H) and number electrons from all sources.

Count protons, count electrons. What do you get?
10 electrons and 11 protons. Could you discuss the charge on the whole entity vs the charge on the individual atoms with examples, please? Here are CH3+ and NH4+. I just learned that the charge on NH4+ is the charge on the whole entity but what's about CH3+?
Title: Re: Why does N get positive charge on it in NH4+ ion?
Post by: Borek on July 24, 2019, 02:41:24 AM
Quote from: IBM on July 23, 2019, 09:24:34 PM
10 electrons and 11 protons.

So what is the resulting charge?
Title: Re: Why does N get positive charge on it in NH4+ ion?
Post by: chenbeier on July 24, 2019, 03:46:25 AM
Quote
what's about CH3+?

It is the same method: Carbon has 6 protons, each Hydrogen has 1 gives 9 Protons total. The number of electrons are 5 for Carbon and 3 for all Hydrogen gives 8.

So you have 9 Protons and 8 Electrons so what is the charge?
Title: Re: Why does N get positive charge on it in NH4+ ion?
Post by: IBM on July 24, 2019, 10:28:42 AM
Quote from: chenbeier on July 24, 2019, 03:46:25 AM
Quote
what's about CH3+?

It is the same method: Carbon has 6 protons, each Hydrogen has 1 gives 9 Protons total. The number of electrons is 5 for Carbon and 3 for all Hydrogen gives 8.

So you have 9 Protons and 8 Electrons so what is the charge?
1 positive charge. But my question is why carbon has 5 electrons? it should have 6 electrons as electrons are the same in number as protons.
Title: Re: Why does N get positive charge on it in NH4+ ion?
Post by: IBM on July 24, 2019, 10:35:03 AM
Quote from: Borek on July 24, 2019, 02:41:24 AM
Quote from: IBM on July 23, 2019, 09:24:34 PM
10 electrons and 11 protons.

So what is the resulting charge?
1 positive charge
Title: Re: Why does N get positive charge on it in NH4+ ion?
Post by: Babcock_Hall on July 24, 2019, 10:49:09 AM
Quote from: IBM on July 24, 2019, 10:28:42 AM
1 positive charge. But my question is why carbon has 5 electrons? it should have 6 electrons as electrons are the same in number as protons.
For a free atom that is electrically neutral, the number of electrons is the same as the number of protons.  One cannot assume that this is true in all situations.