Get CBSE class 12 Chemistry practice paper 2017 for the coming CBSE board examination 2017. This practice paper is as per latest CBSE examination pattern of class 12 Chemistry. All the questions of this practice paper are based on latest CBSE syllabus.
CBSE board exams 2017 are about to start from 1st March 2017 and every student of CBSE class 12 want to score maximum marks in board examinations. CBSE result 2017 of class 12 students will depend on their score in core subjects. This practice paper is developed by subject experts after the brief analysis of CBSE class 12 Chemistry question paper 2016. Some important questions from previous year CBSE papers are also included in this practice paper.
The complete practice paper is given below:
Time allowed: 3 hours Maximum Marks: 70
(i) All questions are compulsory.
(ii) Questions number 1to 5 are very short answer questions and carry 1 mark each.
(iii) Questions number 6 to 10 are very short answer question and carry 2 marks each.
(iv) Questions number 11 to 22 are also short answer question 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 question and carry 5 marks each.
(vii) Use log tables, if necessary. Use of calculators is not allowed.
Question1: Write the structure of an isomer of compound C4H9Br which is most reactive towards SN1 reaction.
Question2: Why CuSO4. 5H2O is blue in colour while CuSO4 is colourless?
Question3: NO2 group show its effect only at ortho- and para- positions and not at meta- position. Explain.
Question4: Write IUPAC name of the given compound:
Question5: Explain the causes of Brownian movement in a colloidal solution?
Question6: The formula of a coordination compound is CoCl3.4NH3. It does not liberate ammonia but precipitates chloride ions as silver chloride.
(i) Write the structural formula of the complex?
(ii) What is the IUPAC name of the complex?
Question7: Explain why alkylamine more basic than ammonia.
Question8: Write mathematical expression of Henry’s law correlating the pressure of a gas and its solubility in a solvent and mention one applications of the law.
Question9: Out of the following two coordination entities which is chiral (optically active)?
(a) cis-[CrCl2(ox)2]3‒ (b) trans-[CrCl2(ox)2]3‒
Question10: Draw the structures of the following molecules:
Question10: Complete the following equations:
(i) HgCl2 + PH3 →?
(ii) XeF4 + H2O →?
Question11: Name the reagents which are used in the following conversions:
(i) A primary alcohol to an aldehyde
(ii) Butan-2-one to butan-2-ol
(iii) Phenol to 2, 4, 6-tribromophenol
Question12: Account for the following observations:
(i) pKb for aniline is more than that for methylamine.
(ii) Methylamine solution in water reacts with ferric chloride solution to produce a precipitate of ferric hydroxide.
(iii) Aniline does not undergo Friedel-Crafts reaction.
Question13: Define the following in relation to proteins :
(i) Primary structure
(iii) Peptide linkage
Question14: What do you understand by flux? What is its role in the metallurgy of iron and copper?
Question15: Give reasons for the following:
(i) Nickel does not form low spin octahedral complexes.
(ii) The p-complexes are known for the transition metals only.
(iii) Co2+ is easily oxidised to Co3+ in the presence of a strong ligand.
Question16: An element has a body-centred cubic (bcc) structure with a cell edge of 288 pm. The density of the element is 7.2 g/cm3. How many atoms are present in 208 g of the element?
Question17: (a) What is the significance of number 6 and 6, 6 in the polymer names nylon-6 and nylon-6, 6?
(b) What is the difference between Buna-N and Buna-S?
(c) Arrange the following polymers in increasing order of their intermolecular forces
Neoprene, Nylon 6, Polyvinyl chloride
Question18: In a pseudo first order hydrolysis of an ester in water, the following results were observed
(i) Find the average rate of reaction between the time intervals 30 to 60 seconds.
(ii) Find the pseudo first order rate constant for the hydrolysis of ester.
Question19: (i) Why alkylamine is more basic than ammonia?
(ii) What are azo dyes?
(iii) What do you understand by coupling reaction?
Question20: What is Corrosion? What are the chemical reactions involved in the formation of corrosion?
Question21: Calculate the boiling point of a 1M aqueous solution (density 1.04 g mL) of Potassium chloride (Kb for water = 0.52 K kg mol−1. Atomic masses: K = 39 u. C1 = 39.9 u). Assume, Potassium chloride is completely dissociated in solution.
Question21: Find the depression in the freezing point of water when 10 g of CH3CH2CHClCOOH is added to 250 gram of water. Kα = 1.4 × 10 ‒ 3, Kf = 1.86 K kg mol‒1.
Question22: Define the following terms:
(b) Tyndall Effect
Question23: Observing the growing cases of diabetes and depression among young children, Mr. Amit, the principal of one reputed school organized a seminar in which he invited parents and principals. They all resolved this issue by strictly banning junk food in school s and introducing healthy snacks and drinks like soup, lassi, milk etc in school canteens. They also decided to make compulsory half an hour of daily physical activities for the students in the morning assembly. After six months, Mr. Amit conducted the health survey in most of the schools and discovered a tremendous improvement in the heath of students.
After reading the above passage answer the following question:
(i) What are the values displayed by Mr. Amit?
(ii) As a student, how can you spread awareness about this issue?
(iii) What are the anti-depressant drugs? Give an example.
(iv) Name the sweetening agent used in the preparation of sweets for a diabetic patient.
Question24: (a) Define molar conductivity of a substance and also write the relationship between molar conductivity and specific conductivity.
(b) A voltaic cell is set up at 25o C with the following half cells:
Ag+ (0.001 M) | Ag and Cu2+ (0.10 M) | Cu
What would be the voltage of this cell? (Eo cell = 0.46 V)
Question24: (a) Describe how for weak and strong electrolytes, molar conductivity changes with concentration of solute. How is such change explained?
(b) Conductivity of 0.00241 M acetic acid is 7.896 × 10‒5 S cm‒1. Find its molar conductivity and if Λo for acetic acid is 390.5 S cm2 mol‒1, what is the dissociation constant?
Question25: (a) How are the following obtained?
(i) Benzoic acid from ethyl benzene.
(ii) Benzaldehyde from toluene.
(b) Complete each synthesis by giving the missing material, reagent or products:
Question25: (a) Name two commonly used methods to convert >C=O group into >CH2 group
(b) Name the products formed when ethanal is heated with hydrogen iodide and red phosphorous under high pressure.
(c) Name the acid present is vinegar.
(d) Identify the compounds X, Y and Z in the following reaction.
Question26: (a) What may be the possible oxidation states of the transition metals with the following d electronic configurations in the ground state of their atoms: 3d 3 4s 2, 3d5 4s 2 & 3d 6 4s 2. Indicate relative stability of oxidation states in each case.
(b) Write steps involved in the preparation of (i) Na2CrO4 from chromite ore and (ii) K2MnO4 from pyrolusite ore.
Question26: Assign reasons for the following
(a) The transition metals and many of their compounds act as good catalysts.
(b) The enthalpies of atomisation of transition elements are high.
(c) From element to element the actinoid contraction is greater than the lanthanoid contraction.
(d) The Eo value for Mn3+/Mn2+ couple is much more positive than that of Cr3+/Cr2+
(e) Scandium (Z = 21) does not exhibit variable oxidation states and yet it is regarded as a transition element.
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