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Chemistry-1998-Set I

Q1) Write the MO electronic configuration of a diatomic molecule having a bond order of three? (Marks 1)
Ans.1) 1s2 *1s2 2s2 *2s2 2px2= 2py2 2pz2 (for example – N2)

Q2) What are non-stoichiometric compounds? (Marks 1)
Ans.2) Non-stoichiometric compounds are in which the ratio of the cation’s to the anions is different from that indicated by the chemical formula.

Q3) Complete the nuclear reaction expression? (Marks 1)
Ans.3) 27Co59 (d, p) 27Co60

Q4) Write the IUPAC name of : (Marks 1)

Ans4) 2 – Phenyl propanol.

Q5) Why do noble gases form compounds with fluorine and oxygen only? (Marks 1)
Ans5) Noble gases have very stable configuration and therefore only the most electronegative elements like fluorine and oxygen are able to oxidise them.

Q6) Why is hydrochloric acid not used to acidify a permanganate solution in volumetric estimations of Fe2+ or C2O42- ? (Marks 1)
Ans6) HCl is not used to acidify a permanganate solution is volumetric estimations of Fe2+ or C2O42- because HCl gets oxidised to Cl2 and some quantity of permanganate is used for this.

Chemistry-1998-Set II

Q3) Write the IUPAC name of [Ni(CN)4]2- ion. (Marks 1)
Ans3) IUPAC name of [Ni(CN)4]2- ion is tetracyanonickelate (II) ion.

Q4) Write the IUPAC name of : (Marks 1)
O

CH3CCHCH3

CH3

Ans4) IUPAC name of
O

CH3CCHCH3 is 3-Methyl-2-butanone.

CH3

Q6) Complete the nuclear reaction expression : (Marks 1)
13AI27(,n)….

Ans6) 13Al27 (,n)15P30

Q9) Why do azo dyes not impart fast colour to fabrics? (Marks 1)
Ans9) Azo dyes do not impart fast colour to fabrics because their interaction with the fabric is one of surface adsorption.

Chemistry-1999-Set I

Q 1 Define an atomic orbital. What does angular momentum quantum number tell about an orbital ?
Ans. 1 Orbital is three dimensional region in space around the nucleus where probability of finding electron is maximum. Angular memento determine the shape of the orbital.

Q 2 Which one of the two, O-2 or O-22 has higher bond order and why?
Ans. 2 O-2 has higher bond order.
O-2 = s 2s2 s*2s2 s2p2z 2p2x 2p2y 2p2x *2p1y
B.O. = 1/2 (8-5) = 1.5
B.O. of O -22 = 1/2 (8-6) = 1

Q 3 Define dislocation in crystal.
Ans. 3 Lattice imperfection extending along a line is known as line defect or dissociation.

Q 4 Write an example of neutral molecule which is isoelectronic to CIO-.
Ans. 4 CIF of HOCl or OF2

Q 5 Express the relationship between degree of dissociation of an electrolyte and its molar.
Ans. 5 = m / m

Q 6 What for are quaternary ammonium salts widely used?
Ans. 6 For detergent.

Q 7 What is meant by Faraday constant?
Ans. 7 It is the charge carried by one mole of electrons or quantity of charge required to deposit one gram equivalent of any element.

Chemistry-1999-Set II

Q 1 Write the number of unpaired electron(s) in an atom of an element with the atomic number 21.
Ans. 1 1

Q 3 How many atoms are there in a unit cell of a metal crystallising in fcc structure?
Ans. 2 4

Q 9 In the formula Fe(h5 – (C5H5)2 what does the prefix ‘h5′ denote.
Ans. h5 – indicate that there are 5 carbon atoms bound to the metal in the compound.

Q 21 For the first row of transition metals the Eo values are :
V Cr Mn Fe Co Ni Cu
Eo(M2+/M) -1.18 -0.91 -1.18 -0.44 -0.28 -0.25 +0.34V

Give suitable explanation for the irregular trend in these values.

Ans. Due to irregular trend in their I.E. values/heat of sublimation/heat as hydration.

Chemistry-1999-Set III

Q 2 In the rock salt structure how many Na+ ions occupy second-nearest neighbour location of a Na+ ion?
Ans. 1 12

Q 3 Which type of hybridisation explains the trigonal bipyramidal shape of SF4 ?
Ans. 2 sp3d

Q 11 Calculate the uncertainity in te velocity of a wagon of mass 3000 kg whose position is known to an accuracy of 10pm. (h = 6.63 x 10-34.Js)
Ans. 3 x.mv > h/ 4
v = h / 4pmv = 6.6 x 1034 / 4 x 3.14 x 3000 x 10 x 10-12.
= 1.75 x 10 -27 ms-1

Q 12(i) What is the basic building unit of all silicates?
(ii) How many oxygen atom of this unit are shared with others in the silicate ion Si3O96- ion?

Ans. 4 (i) SiO4
(ii) 2

Q 23 Draw the structure and write the hybridisation state of the central atom of each of the following species :
(i) [Co(NH3)6]3+
(ii) [NiCl4)]2-)

Ans. 5 (i) d2sp3 structural – octahedral
(ii) sp3 structural – tetrahedarl

Chemistry-2000 Set I

Q.1 What is the physical significance of the lines in the following depiction of atomic orbitals?
Ans1. Lines encloses the regions in the space around the nucleus where there is maximum probability of finding the electron.

Q.2 An ionic compound AB2 possesses CaF2 type crystal structure.
Write the co-ordination numbers of A2+ and B- ions in the crystals of AB2.
Ans2. A2+ = 8 B+ = 4

Q.3 How many state of a thermodynamic system be defined?
Ans3. The state of thermodynamic system can be defined in the term of a state of state variable’s that are – pressure, temperature, volume.

Q.4 State Kohlrausch’s low for electric conductance of an electrolyte at infinite dilution.
Ans4. “At infinite dilution, each ion moves independently and contributes to the total molar conductance of an electrolyte.

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Chemistry-2000 -Set II

Q.1 Write the name and molecular structures of the monomers of the following polymers :
(i) Natural Rubber
(ii) Nylon-66

Ans1. (i) Natural rubber monomer is :
CH3 = CH – CH = CH2
|
CH3 2-methyle-1,3-butadiene (Isoprene)
(ii) Monomers of nylon – 66 are :
H2N-(CH2)6 – NH2 (HexamethyleneDiamine) and HOOC-(CH2)4- COOH(adipic acid)

Q.2 (a) Write a chemical equations and reaction conditions for the conversion of :
(i) Ethene to ethanol
(ii) Phenol to phenyl ethanol
(iii) Ethanol to 2-propanol
(b) Give an for each of the following reactions :
(i) Kolbe’s reaction
(ii) Reimer – Tiemann reaction.
…………………………………………H2SO4

Ans2. (a) (i) CH2 = CH2 + H2O ————–> CH3-CH2 – OH

(ii)
——————————————–H3+O
(iii) CH3CHO + CH3MgBr ———————-> CH3-CH-CH3
………………………………………………………………|
……………………………………………………………OH

(b) Kolbe’s Reaction :

(c) Reimer-Timen reaction :

Q.3 (a) Account for the following observation :
(i) Berillium resembles Aluminium in several properties
(ii) The +2 oxidation state of lead is more satable than the +2 oxidation state of tin.
(iii) CO2 is a gas but SiO2 is a solid.
(iv) Hydrogen fluoride has heigher boiling point than hydrogen chloride.
(b) drow the structure of XeF4 molecule. (atomic number Xe = 54)

Ans3. (i) Be and Al are palced diagonally to each other in adjacent groups. The diagonally placed elements show resemblance to each other because of almost similar atomic parameters.
(ii) Pb is more stable in +2 because of inert pair effect.
(iii) CO2 exists as discrete molecules having weak forces of attraction amongest molecules. O = C = O
Unlike ‘C’ , Si acn not form p- p bonds and completes its tetracovalancy by forming a three dimensional network of covalent bonds resulting into the formation of a giant network solid.
(iv) H-F has higher boiling point because of association of molecules through intermolecular H- bonds.

Chemistry-2000 Set III

Q.1 Define the term denaturation in relation of protein.
Ans1. Disruption of native conformation of a protein due to change in pH, temperature, salts and the likes, is called denaturation.

Q.2 What are the properties of
(i) Ferromagnetics and
(ii) ferroelectrics? Give an example of each type.

Ans2. Ferromagnetic substance are those which show attraction towards external magnetic field and show a permanent magnetism even when the magnetic field is removed. In such substance large number of unpaired electrons aligned in same direction are present.
Example : Fe
Ferroelectric solids are those piezoelectric solids in which permanent dipole present are spontaneously polarised even in the absence of electric field and the direction of polarisation can be changed by applying an electric field.
Example : Barium Titanate (BaTiO3), Rochelle salt.

Q.3 (a) How and where is carbon-14 produced in nature and how it is incorporated into living plant?
(b) Write the principle of radiocarbon dating.

Ans3. (i) Radioactive isotopes carbon-14 is formed by the bombardment of nitrogen in the upper atmosphere by cosmic rays :
147 N + 10 n ——-> 146 C + 11H
The C-14 produced is eventually incorporated into the carbondioxide of air which in turn is incorporated into living plants by the process of photosynthesis and then finds its way into the animal which eats plant.
(ii) The principle of the radiocarbon dating is based on the fact that living matter contains a definite proportion of the radioactive C-14. Once the plant or animal dies, the process of incorporation of carbon stops. And already present ready to decay.
146 C —-> 147 N + O-1e; t1/2 = 5770 years
By knowing the equilibrium concentration of C-14 in a living plant and the concentration of C-14 in a dead piece of organic matter at a particular time, the age of the material can be determined.

Business Studies-1997-Set I

Q 1 What is meant by management? (2 marks)
Ans. 1 Management may be defined as creating the internal environment of an enterprise where individuals working together in groups can perform efficiently and effectively towards the attainment of group goals.

Q 2 Explain, in brief, the principle of parity of authority and responsibility. (2 marks)
Ans. 2 Authority is the right to give orders to the subordinate, take decision on specified matters, use resources of the organisation and guide and regulate the behaviours of the subordinates.

Responsibility means the duty which the subordinate is expected to perform by virtue of his position in the organisation. The principle states that authority and responsibility should bear a logical relation to each other. Sufficient authority should be delegated to a subordinate to enable him to discharge his duties. If authority is less, the subordinate will not be able to perform his duties well. If he is given excessive authority he may misuse.

Authority ½, Responsibility ½ , Parity 1 (1/2 +1/2+1=2 marks)

Q 3 Give two functions of a supervisor. (2 marks)
Ans. 3 Any Two functions :
1. Planning the work.
2. Issuing orders.
3. Providing guidance or leadership.
4. Motivation.
5. Preserving Records.
6. Controlling output.
7. Grievance handling or liaison between management and workers.
8. Introducing new work methods.
9. Enforcing safety.
10. Linking pin.
11. Scheduling.
12. Reporting. (1×2=2)

Q 4 Explain briefly the meaning of “organisation structure”.
(3 marks)

Ans. 4 The process of organising leads to the creation of the structure of an organisation. The term organisation structure may be defined as a system of job positions, the roles assigned to them and the authority relationships among the various positions. The structure provides basis or frame work for managers and other employees for performing their respective functions. The structure also facilitates work flow in the organisation. If a chart is prepared, the organisational structure looks like a pyramid with a narrow top and broad bottom. (3 Marks)

Business Studies-1997-Set II

Q 1 What is meant by management? (2 marks)
Ans. 1 Management may be defined as creating the internal environment of an enterprise where individuals working together in groups can perform efficiently and effectively towards the attainment of group goals.
Note : If the student has given a definition other than this, full credit may be given. (2 marks)

Q 2 Explain, in brief, the principle of Esprit de Corps. (2 marks)
Ans. 2 Principle of Esprit de Corps :
It refers to team spirit that is harmony in group work and mutual understanding among workers. Managers must take steps to develop a sense of belonging among the members of a work group. If there is team spirit, everyone comes forward to help others. It helps in developing an atmosphere of mutual trust and understanding. People them enjoy working in an organisation. It inspires them to work harder and improve the quality of work. When esprit de corps is present, the need to use penalties for default is minimised. (2 marks)

Q 3 Give any two elements of directing. (3 Marks)
Ans. 3 Any two of the following elements of direction :
(i) Leadership
(ii) Communication
(iii) Motivation
(iv) Supervision (1×2 marks)

Q 4 Explain briefly the steps in the process of organising. (3 Marks)
Ans. 4 The steps in the process of organising with brief explanation :
(i) Division of work.
(ii) Grouping jobs and departmentation.
(iii) Establishing authority relationship. (1×3 marks)

Q 5 Give any three main features of the line organisation. (4 Marks)
Ans. 5 Any three of the following main features of line organisation :
(i) It is simple type of organisation.
(ii) Only one form of authority, viz.; line authority exists in this form of organisation.
(iii) The authority relationships are clearly established.
(iv) All managers in a line organisation have full authority to decide things and to act with respect to their respective functions.
(v) In a line organisation departments are created for basic activities each of which is self-contained as the related services are also part of the activities of the departmental head.
(vi) Specialised, supportive activities are not specifically recognised and distinguished in a line organisation. (1×3 marks)

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