An organic compound A with molecular form C₄H₈O₂ on alkaline hydrolysis gives two compound B and C. C on acidification with dil. HCl gives D. Oxidation of B with K₂Cr₂O₇/H₂SO₄ also gives D. Identify A, B, C and D and explain all the reactions involved.

Give the reaction for the hydrogenation of unsaturated carbon compounds. Define the term catalyst and name the catalyst used in this reaction. Which oil should be chosen for cooking and why?

Give account of chemical properties?

(i) combustion of ethanol

(ii) oxidation of ethanol

(iii) reaction of C₂H₅OH with sodium metal

(iv) dehydration of C₂H₅OH

(v) reaction of C₂H₅OH with ethanoic acid

Have you ever observed while cleaning cloth that foam is formed with difficulty and an insoluble substance (scum) remains after washing with water? This is caused by the reaction of soap with the calcium and magnesium salts, which cause the hardness of water. Hence, you need to use a larger amount of soap. This problem is overcome by using another class of compounds called detergents as cleansing agents. Detergents are generally ammonium or sulphonate salts of long chain carboxylic acids. The charged ends of these compounds do not form insoluble precipitates with the calcium and magnesium ions in hard water. Thus, they remain effective in hard water. Detergents are usually used to make shampoos and products for cleaning clothes.

(i) How will you test the hardness of water?

(ii) Why soap forms scum (insoluble substance) with hard water?

(iii) How one can overcome the problem of scum formation? What values do you identify in this context?

Consider the following statements related to diamond and graphite.

I. Both diamond and graphite are used as abrasives.

II. Diamond and graphite have different arrangements of carbon atoms.

III. The carbon atoms in graphite have a different number of neutrons from those in diamond.

IV. The carbon atoms in both graphite and diamond have four single covalent bonds. The incorrect statement(s) is/are