Why reducing nature of hydrides increases down a group?

[Raghav Gupta]

I have never read about basic nature of hydrides. They are known to be reducing agents. Alkali metal hydrides react with water liberating hydrogen gas and a hydroxide. Also such hudrides are called salt-like hydrides not acidic or basic hydrides. But non metal hydrides are basic like NH3.

But when comparing acidity of NH3,PH3,AsH3,SbH3 we say that Down the group acidity increases which is analogue to up the group basicity increases?

 

[AdityaDev]

That is because of low electron density at central atom. As size increases, the electron density around central metal atom decreases hence basicity decreases.

 

[Raghav Gupta]

That is because of low electron density at central atom. As size increases, the electron density around central metal atom decreases hence basicity decreases.

So why that statement is wrong in case of oxides of that group?

 

[Raghav Gupta]

I would strongly advise you to read this up . It will give you an idea for your halogen statement .

In continuation with post #25 why then group 16? Wiki is showing that they are not hydrides but like hydrogen selenide, hydrogen oxide etc.

 

[Jack2]

In continuation with post #25 why then group 16? Wiki is showing that they are not hydrides but like hydrogen selenide, hydrogen oxide etc.

Hydride mean a hydrogen atom with a negative charge .
In all halogens , hydrogen has +1 charge . They are called acids , not hydrides .
In group 16 , the lower elements are metallic ( having EN less than 2.1 ) so their compounds can be called hydrides . So I made a generalized statement .
But surely halogen groups don't form hydrides .

 

[Raghav Gupta]

Why the generalized statement , when only in that group Polonium is a metal? It should be called a exception from 16 group.
and what about this?

I was reading that but there the wikipedian has written citation needed where he/she is saying following compounds are hydrogen and not hydrides, means he/she can be lying.

Basically what I meant in this thread is hydrogen bonding to elements whether it would be a hydride or hydrogen that's all nomenclature but a hydrogen is hydrogen.
Now one can also argue with oxides, there are peroxides, superoxides. But what really matter is linkage of element with oxygen.

 

[Borek]

To all - please keep your posts on topic and if you have new questions, start a new thread.

 

[Raghav Gupta]

To all - please keep your posts on topic and if you have new questions, start a new thread.

I few days ago started a new thread but got only one reply and none then.
Even if you have said I don't know it would have been fine( I know elders hesitate to say this sometimes but then also basic etiquettes are required).

Anyway I agree with you that for new questions new thread must be started and by the way excluding 2 threads you have helped me a lot in chemistry.
But any comment or reply for first para?