Bihar Board 12th Chemistry Questions4:55 pm
Bihar Intermediate Education Board is the education board in Bihar which controls the intermediate exams in the state. The Bihar School Examination Board conducts class 12th examination every year. In this section, find the latest sample paper of Chemistry class 12 according to latest syllabus including all the topics. The questions of the examination is given below, with the intent of providing assistance to the students we provide the sample paper. Still if it contains any error ans if it needs any type of improvement please do let us know. Please give your valuable feedback through the comment sections, Any type of suggestions will be highly appreciated.
Time: 3 Hrs 15 minutes(extra)
Total Marks: 70
Directions to Questions: Choose from the correct option
1.The oxidation state of Nickel in [Ni(CO)4] is:
(a) 1 (b) 3 (c) 0 (d) 2
2. If dispersed phase is liquid and dispersion medium is solid, the colloid is known as:-
(a) A Sol (b) A gel (c) An emulsion (d) A foam
4.Which of the following is not a condensation polymer?
(B) Nylon – 6, 6
5. The reaction of Cl2 with hot Na-OH gives
(A) Na-cl, NaClO3
(C) Na-cl, NaOCl
6.The unit of rate constant of First order reaction is
(A) Time -1
(B) Mole liter -1 sec -1
(C) Liter mole -1 sec -1
(D) Liter mole -1 sec
7. The antiseptic action of CHI3 is due to
(B) Liberation of free iodine
(C) Partially due to iodine and partially due to CHI3 itself
(D) None of these
8. Which of the following chemicals are used as anesthetic:
9.Titanium shows magnetic moment of 1.73 B.M in its compound. What is the oxidation number of Ti in the compound.)
10. Methyl amine can be prepared by :
(A) Wurtz reaction
(B) Friedel- craft’s reaction
(C) Hoffman Bromamide reaction
(D) Clemmension reaction
Directions to the Questions from 11 to 15: The questions have two Statements and there are four options a, b, c, d. On the Basis of the given Statement Choose the correct option. Marks Awarded: 5 × 1 = 5
(a) If both the statements are true and statement II is the correct explanation of statement I.
(b) If both the statements are true and statement II is not the correct explanation of statement I.
(c) If statement I is true and statement II is false.
(d) If statement I is false and statement II is true.
Statement I: Bauxite is an ore of aluminum.
Statement II: The formula of bauxite is Al2O3
Statement I: Chloroform does not give white ppt. of Ag-Cl with AgNO3
Statement II: CHCl3 does not contains free chlorine.
Statement II: All ores are minerals.
Statement II: All minerals are ore.
Statement I : Depression in freezing-point is a colligative property
Statement II: Elevation in boiling point is a colligative property.
Statement I: Iron get corroded readily in moist air.
Statement II:Free energy of the process is positive.
Directions to Questions From 16 t0 18: The Questions contain more than one correct answer. Choose the correct answer. Marks Awarded- 3 × 1 = 3
16. Dolomite mineral contains.
Answer- a, c
17. Benzyl chloride can be prepared from toluene by chlorination with.
18. Which of the following are colloids?
(C) Urea solution
Answer- a, d
Directions to Questions from 19 to 22: There are two columns. Match From Column I with Column II. Marks Awarded-4 × 1 = 4
19. Grignard reagent (A) Protective colloid
20. Freon (B) R Mg X
21. Emulsion (C) CF2Cl2
22. Gelatin (D) Milk
Answer- 19-(b) 20 (c) 21- (d) 22-(a)
Directions to Questions from 23 to 25: There is Passage given Below. Choose the correct answer from the options after reading the passage.
Order of the reaction is the sum of concentration terms on which the rate of a reaction actually depends as observed experimentally. Order can be zero, whole number or in fraction.
23.In a reaction the units of rate constant are equal to the rate of reaction. The order of reaction is.
(A) Zero order
(B) First order
(C) Second order
(D) Pseudo uni molecular
24. In the reaction 2NO + O2 → 2NO2 the unit of rate constant is.
(A) MoIL–1 S–1
(B) Mol–1 LS–1
(C) bar–1 S–1
(D) Lit2 Mol–2 Sec–1
25. One example of pseudo uni-molecular reaction.
(A) H2+ Cl2> → 2HCl
(B) CH3COOC2H5 + H2O H+ ⎯⎯→ CH3COOH + C2H5OH
(C) CH3CHO → CH4 + CO
(D) 2NO + O2 → 2NO2
NON-OBJECTIVE TYPE Questions
SHORT ANSWER TYPE QUESTIONS
Q. No. 1 to 11 are short answer types questions. Each question carries 3 marks.
11 × 2 =22
ANS: Polymerization is a process in which macro molecule is formed as a union of smaller molecules with or without elimination of a molecule like H2O, HCl. Smaller molecule is known as monomers and bigger one is called as polymer.
2. What is the co-ordination number of the central metal ions in the following complexes?
(i) K2 [Ni (CN)4]
(ii) [Co (NH3)6] Cl
(iii) [Ag (CN)2]
ANS: The co-ordination number of the following complexes are:
3. What are primary, secondary and tertiary alcohols? Give one example of each.
ANS: Examples of primary alcohol– R– CH OH,
Secondary alcohol—CH OH CH CH OH,
Tertiary alcohol: CH CH CH OH
4. How are synthetic detergents better than soaps?
ANS: The synthetic detergents are better than soaps in the following ways:
(i) Soap can only be used in soft water since in hard water calcium and magnesium present . produces crude white precipitate of calcium.
(ii) Soap can not be used in acidic solutions
(iii) Soap does not have the ability to remove oil and grease.
5. 4g of caustic soda (molar mass = 40) is dissolved in water and the solution is made to 200 cm3. Calculate the molarity of the solution.
ANS: 1000 cc – 40gm – N Solution
1000 cc – 4 gm – N/10 Solution
∴ 200cc – 4gm =N / 10 × 5 =N / 2
6. Write I.U.P.A.C. name of the following compounds.
ANS: (i) Methylethanamine
7. Give one example of a neutral amino acid. Why is it neutral in nature ?
ANS: It is neutral because it contains equal number of acidic COOH and basic NH2 group.
8. Why D-fructose used for sweetening cold drink but not hot ones ?
ANS: The sweeter form is fructopyranose on high temperature causes a shift in the
equilibrium towards less sweet furanose.
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