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Potassium Hydride in water

Screen Shot 2018-05-17 at 16.49.03.png
I thought the answer was B, lilac means it is potassium. And the metal oxide is basic?
The mark scheme says it's D.
Original post by Feynboy
Screen Shot 2018-05-17 at 16.49.03.png
I thought the answer was B, lilac means it is potassium. And the metal oxide is basic?
The mark scheme says it's D.


How could potassium oxide react with water to give off hydrogen gas?
Reply 2
Original post by Plantagenet Crown
How could potassium oxide react with water to give off hydrogen gas?


oh yeah. Ok then
Original post by Feynboy
oh yeah. Ok then


Hydrides of group 1, such as KH, contain the H- ion.

They react with water to form:

H- + H2O --> H2 + OH-

hydrogen and hydroxide ions ...

Interestingly, this is an example of a synproportionation (comproportionation) reaction where one element in two different oxidation states becomes the same oxidation state. It is the chemical opposite of disproportionation.
(edited 5 years ago)
Reply 4
Original post by charco
Hydrides of group 1, such as KH, contain the H- ion.

They react with water to form:

H- + H2O --> H2 + OH-

hydrogen and hydroxide ions ...

Interestingly, this is an example of a synproportionation (comproportionation) reaction where one element in two different oxidation states becomes the same oxidation state. It is the chemical opposite of disproportionation.


Thank you :smile:

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