FAHAHEEL AL WATANEIH INDIAN PRIVATE SCHOOL

Size: px

Start display at page:

Download "FAHAHEEL AL WATANEIH INDIAN PRIVATE SCHOOL"

Linette Horn
5 years ago
Views:

FAHAHEEL AL WATANEIH INDIAN PRIVATE SCHOOL AHMADI KUWAIT II TERM EXAMINATION(2016-2017) CHEMISTRY CLASS XII SET 1 General Instructions: All questions are compulsory.

1 FAHAHEEL AL WATANEIH INDIAN PRIVATE SCHOOL AHMADI KUWAIT II TERM EXAMINATION( ) CHEMISTRY CLASS XII SET 1 General Instructions: All questions are compulsory. Question numbers 1 to 5 are very short answer questions each of 1 mark. Question numbers 6 to 10 are short answer questions each of 2 marks. Question numbers 11 to 22 are short answer questions each of 3 marks. Question number 23 is a long answer question of 4 marks. Question numbers 24 to 26 are long answer questions each of 5 marks. Use logarithm tables if necessary. Calculators are not permitted. Time Allowed: 3 hours Total No. of Pages: 5 Maximum marks: Predict the major product formed by the acid catalyzed dehydration of pentan-2-ol A solid is made up of two elements A and B. Atoms A are in ccp arrangement while atoms B occupy 2/3 rd of the tetrahedral voids. What is the formula of the compound? 1 3. Write the structural formula of 2- Phenylethanoic acid What are anionic detergents? Give one example p- nitrophenol has a higher boiling point than o-nitrophenol. Why? 1 6. Account for the following: (i) An increase in temperature is observed on mixing chloroform and acetone. (ii) Measurement of osmotic pressure is widely used for determining molar masses of macromolecules Differentiate between retention and inversion Complete the following chemical equations: (i) P 4 + SOCl 2 (ii) XeF 4 + H 2 O 2 9. Illustrate the following reactions using suitable examples: (i) Ammonolysis (ii) Gabriel phthalimide synthesis 2 1 P a g e

2 9. Write short notes on: (i) Hoffmann Bromamide degradation reaction (ii) Coupling reaction The decomposition of ammonia on platinum surface is a zero order reaction. What are the rates of production of N 2 and H 2 if the rate constant is 2.5 x 10-4 moll -1 s Draw the structures of the following molecules: (i) BrF 3 (ii) (HPO 3 ) 3 (iii) H 2 S 2 O (a) Predict the mechanism for the reaction of ethanol with conc. H 2 SO 4 at 443K. (b) Between p- methoxyphenol and p-nitrophenol, which one is more acidic and why? (2, 1) 13. Consider the reaction, R P. From the following plot answer the given questions: (i) What is the order of the reaction? (ii) What does the slope of the line indicate? (iii) For the reaction, show that the time required for 87.5% completion is 4 times the time required for 50% completion (i) Write the differential rate expression for a hypothetical reaction, R P which follows first order kinetics. (ii) For a hypothetical reaction: A B, the rate of the reaction becomes 27 times when the concentration of A is increased three times. What is the order of the reaction? (ii) Show that the half- life for a first order reaction is independent of the initial concentration of the reactant (a)give the IUPAC names of: (i) HOOC CH 2 CH (COOH) CH 2 COOH 2 P a g e

3 (b) Write the structure of the product formed when tert-buyl alcohol reacts with Cu at 573K. 15. Answer the following questions: ( 2, 1 ) (i) Why are alkyl halides immiscible with water? (ii)why is butan-1-ol optically inactive but butan-2-ol optically active? (iii) Although chlorine is an electron withdrawing group, yet it is ortho and para directing in electrophilic aromatic substitution reactions. Why? (a) What type of stoichiometric point defect is shown by KCl crystal and why? (b) An element crystallizes in body centred cubic structure. If the edge length of the unit cell is 146.9pm and the density is 19.3g cm -3, calculate the atomic mass of the element. [ Given: Avogadro s number = x ] Answer the following questions: (i) Write the structure and name of the product obtained when glucose is treated with conc. nitric acid. (ii) Name the vitamin whose deficiency leads to RBC deficiency in hemoglobin. (iii) How do you explain the amphoteric nature of amino acids? Give reasons for the following: (i) Unlike primary and secondary amines, tertiary amines do not undergo acylation reaction. (ii) Although amino group is ortho, para directing, aniline on nitration gives a substantial amount of m-nitroaniline. (iii) Name the reagent/ reagents which brings about the transformation of ethyl amine to ethyl isocyanide Write the structural differences between: (i) α D glucose and β D glucose (ii) Starch and glycogen (iii) Nucleoside and nucleotide What mass of calcium chloride (molar mass 111g mol -1 ) must be dissolved in 200g of water to raise the boiling point by 0.69K assuming complete dissociation. (k b for H 2 O = 0.512KKgmol -1 ) Explain the following terms: (i) Glycosidic linkage (ii) Inversion of cane sugar (iii) Essential amino acids (a) Arrange the following compounds in the increasing order of basic character in aqueous medium giving reason: 3 P a g e (CH 3 ) 3 N, (CH 3 ) 2 NH, CH 3 NH 2 and NH 3 (b) Convert aniline to para nitroaniline (2, 1)

4 23. Seeing the growing cases of diabetes and depression among young children, Mr. Sharma, the principal of a reputed school organized a seminar for parents and principals of other schools. They all resolved the problem by banning junk foods and introducing healthy snacks and drinks in school canteens. After six months, Mr. Sharma conducted a health survey among students of different schools and found a tremendous improvement in the health of students. : Answer the following questions: (i) What are the values displayed by Mr.Sharma? (ii) What are antidepressant drugs? Give one example. (iii) Why are diabetic patients advised to take artificial sweeteners? (iv) What does the term, drug targets mean in in medicinal chemistry? (a)account for the following: (i) Bi (V) is a stronger oxidizing agent than Sb (V). (ii) There is a large difference between the melting points of oxygen and sulphur. (iii) Nitrogen does not form pentahalides. (b) Arrange the following in order of property indicated for each set: (i) HF, HCl, HBr, HI (Increasing acidic strength) (ii) NH 3, PH 3, AsH 3, SbH 3, BiH 3 ( Increasing basic strength ) (3,2) 24. (a) Account for the following: (i) In solution of H 2 SO 4 in water, the second dissociation constant is Ka 2 is less than the first dissociation constant Ka 1. (ii) Noble gases have very low boiling points. (iii) Fluorine is a stronger oxidizing agent than chlorine. (b) Arrange the following in order of property indicated for each set: (i) H 2 O, H 2 S, H 2 Se, H 2 Te (Increasing thermal stability) (ii) HOCl, HOBr, HOI (Increasing acidic strength) (3,2) 25. (a) Distinguish between the following pairs of compounds using a suitable chemical test: (i) Benzoic acid and benzaldehyde (ii) Propanal and propanone (b) An organic compound A with molecular formula C 9 H 10 O forms 2, 4- DNP derivative, reduces Tollen s reagent and undergoes Cannizzaro reaction. On vigorous oxidation it gives benzene-1,2- dicarboxylic acid. Identify the compound A and write the reactions involved. (c) Aldehydes are more reactive than ketones. Explain. (2, 2,1) 4 P a g e

5 25. (a) Write the structures of A, B, C and D in the following reactions: (b) Distinguish between the following pairs of compounds using suitable chemical tests: (i) Acetophenone and propiophenone (ii) Benzoic acid and phenol (c) The boiling points of carbonyl compounds are higher than hydrocarbons of comparable molecular masses. Explain. (2, 2, 1) 26. (a) Define conductivity of an electrolyte and explain its variation with change in concentration for a weak and a strong electrolyte. (b) The molar conductivity of 0.025M methanoic acid is 46.1Scm 2 mol -1. If the limiting molar conductivity of methanoic acid is 404.2Scm 2 mol -1, calculate the degree of dissociation and dissociation constant of methanoic acid. (2, 3) 26. (a) State Faraday s first law of electrolysis. (b)how much charge in coulombs is required for the reduction of 1 mole of MnO 4 to Mn 2+? (c) Calculate the EMF of following cell at 298K: Mg(s) / Mg 2+ (0.1M) Ag + (0.01M) / Ag(s) [Given: E Θ Mg 2+/ Mg = 2.36 V, E Θ Ag + / Ag = V] (1, 1, 3) xxxxxxxxxxxxxxxxxxxxx 5 P a g e

CHEMISTRY. Time : 3 Hrs. Max. Marks : 70

CHEMISTRY. Time : 3 Hrs. Max. Marks : 70 CHEMISTRY Time : 3 Hrs. Max. Marks : 70 General instructions 1. All questions are compulsory. 2. Q.no. 1-5 are very short answer questions & carry 1 marks each Section-A. 3. Q.no. 6-12 are short answer