(Download) CBSE Class-12 Sample Paper And Marking Scheme 2017-18 : Chemistry
(i) All questions are compulsory.
(ii) Questions number 1 to 5 are very short answer questions and carry 1 mark each.
(iii) Questions number 6 to 10 are short answer questions and carry 2 marks each.
(iv) Questions number 11 to 22 are also short answer questions and carry 3 marks each.
(v) Question number 23 is a value based question and carry 4 marks.
(vi) Questions number 24 to 26 are long answer questions and carry 5 marks each.
(vii) Use log tables, if necessary. Use of calculators is not allowed
1. (CH3)3C—CHO does not undergo aldol condensation. Comment. 1
2. In the process of wine making, ripened grapes are crushed so that sugar and enzyme should come in contact with each other and fermentation should start. What will happen if anaerobic conditions are not maintained during this process? 1
3. A coordination compound with molecular formula CrCl3.4H2O precipitates one mole of AgCl with AgNO3 solution. Its molar conductivity is found to be equivalent to two ions. What is the structural formula and name of the compound? 1
4. How is Brownian movement responsible for the stability of sols? 1
5. In the Arrhenius equation, what does the factor RT -Ea/RT corresponds to? 1
6. (i) Allyl cholride can be distinguished from Vinyl chloride by NaOH and silver nitrate test. Comment.
(ii) Alkyl halide reacts with Lithium aluminium hydride to give alkane. Name the attacking reagent which will bring out this change.2
7. Which of the following solutions has higher freezing point?
0.05 M Al2(SO4)3 , 0.1 M K3[Fe(CN)6] Justify. 2
8. Calculate the emf of the following cell at 298 K :