dse chem questions

Yuki

2014-07-15 8:04 am

1. How to determine the oxidation number of carbon in organic compounds?eg. CH3COOH and CH3CH2OH
2. Do alkenes react with HCl?3. Each water molecule can form at most 4 hydrogen bonds but only 2 onaverage
Each HF molecule can form at most 4 hydrogen bonds but only 1 on averageEach NH3 molecule can form atmost 4 hydrogen bonds but only 1 on averageAre these sentences correct?4. Why does wax act as fuel in gaseous state in a burning candle but notsolid or liquid state?5. #33 Ans: D
why is (3) correct? it produces CO2 as well?
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6. #84 Ans:D why are (3) and (4) correct?

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Thanks so much!!!!!

回答 (1)

己式庚辛

2014-07-15 8:48 pm

✔ 最佳答案

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2014-07-16 02:25:28 補充：
As far as I know, not all kinds of iron oxides are porous. It depends on the precursor and route of formation.
Normal rusting involves hydrated iron(II) oxide and hydrated iron(III) oxides and hydroxides, which are flaky and porous.

2014-07-16 02:28:41 補充：
But by quick oxidation under highly oxidizing conditions, the oxide layer does not expand too much, thus forming a smoother, tighter oxide layer.

2014-07-16 02:30:01 補充：
p.s. gold and platinum can be dissolved by a 3:1 mix of hydrochloric acid and nitric acid, aka Aqua Regia, thanks to the oxidizing medium and the promotion of formation of chlorine-containing (soluble) complex ions.

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