[Rutherford]

1.Has 4-methyl-2-penthanon an optical passive enol form? I thought yes, but in answer is not.

2.Aniline and cyclohexancarboxamide are dissolved in ether. First is added HCl, and then NaOH. Which substance reacted with which reagent? I don't know how to solve this.

3.When  0.328g of acetyl bromide reacts with ethanol in excess, ethyl-acetate and HBr are made. On cold, the obtained compounds react with 20ml of 0.12M NaOH, while on warm it reacts with two times more moles of NaOH. Why? I know that HBr reacts with NaOH, but why is there a difference on higher temperature?

[discodermolide]

1.Has 4-methyl-2-penthanon an optical passive enol form? I thought yes, but in answer is not.

2.Aniline and cyclohexancarboxamide are dissolved in ether. First is added HCl, and then NaOH. Which substance reacted with which reagent? I don't know how to solve this.

3.When  0.328g of acetyl bromide reacts with ethanol in excess, ethyl-acetate and HBr are made. On cold, the obtained compounds react with 20ml of 0.12M NaOH, while on warm it reacts with two times more moles of NaOH. Why? I know that HBr reacts with NaOH, but why is there a difference on higher temperature?

Question 1 sorry I do not understand what you mean.

Question 2 Aniline reacts with HCl because it is an amine, basic, the other compound is an amide and will be hydrolysed by the base NaOH.
Question 3 When warm NaOH will hydrolyse the ester, hence 2 moles of NaOH are consumed. 1 for the HBr, 1 for the ester hydrolysis.

[Rutherford]

Thanks for the answers.
1st question, 4-methyl-2-penthanon is a ketone that has different enol forms. Is any of those enols optical inactive?

[discodermolide]

Thanks for the answers.
1st question, 4-methyl-2-penthanon is a ketone that has different enol forms. Is any of those enols optical inactive?

You mean 4-methylpentan-2-one.
It has three possible enol forms, none of which can be optically active. (I forgot the cis isomer in the right hand molecule in the drawing! Sorry)

[Rutherford]

Okay, thanks, then it is surely a mistake in the answer.