Chemistry moles

Please could I have help on part ci, ciii and civ? I thoght for ci when you react potassium hydroxide with the remaining carbon dioxide potassium carbonate and water is made so I don’t understand how it is oxygen? I also don’t understand how to calculate iii and iv? Thank you so much!!

(edited 6 months ago)

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Reply 1

BankaiGintoki

Original post by Ashirs

Please add your question

Reply 2

Ashirs

Sorry I’ve edited the original post with the question. Thanks

Reply 3

BankaiGintoki

Original post by Ashirs

Sorry I’ve edited the original post with the question. Thanks

Ci) is oxygen, as it is in excess, as it is cooled, water vapour is condensed to liquid, which it is why it is 40cm3 after cooling, not 60cm3. Than KOH absorbs the CO2. As all of compound A is reacted (due to oxygen being excess), it can only be oxygen.
Hence now cii) You know it is CO2 as it is acidic… CO2 in (aq) solution produces carbonic acid, H2CO3.
Iii) 40 (before KOH) - 30 (after KOH) = 10 cm3
Iv) 50cm3 (at the start) - 30 cm3 of oxygen (at the end) = 20cm3. The reasoning explained in ci)