Chemistry Sample Papers-1 NIOS Sr. Secondary
Chemistry Sample Papers for Sr. Secondary(Class 12) based on National Institute of Open Schooling (NIOS) latest syllabus.
Chemistry [313]
Time: 3 hours
Maximum Marks: 80
Note:
i. All questions are complsory.
ii. Marks alloted are indicated against each question.
iii. Each questions from question number 1-10 has four alternaives a, b, c and d out of which one is most appropriate. Choose the correct answer among the four alternatives and write it in your answer-book against the question number. No extra time is alloted for attempting multiple choice questions.
Time: 3 hours
Maximum Marks: 80
Note:
i. All questions are complsory.
ii. Marks alloted are indicated against each question.
iii. Each questions from question number 1-10 has four alternaives a, b, c and d out of which one is most appropriate. Choose the correct answer among the four alternatives and write it in your answer-book against the question number. No extra time is alloted for attempting multiple choice questions.
1. The shape of the orbital with value l = 1 is
a. Spherical
b. Tringular Planar
c. Tetrahedral
d. Dumb-bell
2. The compressibility factor of an ideal gas is equal to
a. zero
b. One
c. Ten
d. Infinite
3. Which of the following is most acidic solution
a. pH = 6
b. pH = 5
c. pH = 3
d. pH = 1
4. Which of the following is not colored
a. Mn+3
b. Ti+3
c. Cr+3
d. Se+3
5. Which among the following is most reactive to give nucleophilic addition
a. FCH2CHO
b. ClCH2CHO
c. BrCH2CHO
d. ICH2CHO
6. The internal resistance to flow of a liquid is called
a. Surface tension
b. Viscosity
c. Refractive index
d. Tyndal effect
7. A cricket ball of mass 0.5kg is moving with a velocity of 100 m.s–1, the wavelength associated with its motion is
a. 13.25 × 10–34m
b. 13.25 × 10–366m
c. 6.6 × 10–34m
d. 13.25 × 10–26m
8. Electrode potential for the following half-cell reactions are
Zn → Zn+2 + 2e, Eo = +0.76V
Fe → Fe+2 + 2e, Eo = +0.44V
The EMF for the cell reaction
Fe+2 + Zn → Zn+2 + Fe will be
a. –0.32V
b. +1.20V
c. –1.20V
d. +0.32V
9. Which of the following will not give aldol condensation
a. Phenyl acetaldehyde
b. 2-methylpentanal
c. Benzaldehyde
d. 1-phenylpropanone
10. Which of the following properties of colloids does not depend on the charge on particles
a. Coagulation
b. Electro-osmosis
c. Electrophoresis
d. Tyndall effect
Question Number 11-19: 2 Marks
11. Write down the expressions for Kp and Kc for the following reaction. How are they related?
CaCO3(s) ⇌ CaO(s) + CO2(g)
12. Explain in which of the following compounds, the chemical bond would have less ionic character LiCl or KCl.
13. An aqueous solution of sodium chloride freezes below 273 K. Explain the lowering in freezing points of water with the help of a suitable diagram.
14. How are the following colloidal solutions prepared?
a. Sulphur in water
b. Gold in water
15. If the uncertainty in the velocities of two particles A and B with masses of 1.0 × 10-27 kg and 1.0 × 10-31 kg, respectively, is the same, what will be the ratio of uncertainty in their positions?
16. If the activation energy of a reaction is zero, will the rate of reaction still depend on temperature? Explain.
17. Describe the following giving the relevant chemical equation in each case
a. Carbylamine reaction
b. Hofmann’s bromamide reaction
18. What are biodegradable polymers? Give two exampples.
19. What is the half life period of a reaction? Calculate the half life period of a first order reaction?
Question Number 20-26: 4 Marks
20. Water can hydrolyse only one out of CCl4 and SiCl4. Which one of the two is hydrolysed? Write down the hydrolysis reaction and name the main product formed. Explain, why it is possible in one case and not in the other.
21. The standard enthalpies of formation of CO2(g), H2O(l) and CH4(g) are -393.5, - 286.2 and -74.8kJ/mol respectively. Calculate the enthalpy of combustion of methane.
22. Explain what is inert pair effect. What are its causes?
23. What is stereoisomerism? Which type of stereoisomerism is shown by 1,2-dichloroethene? Draw the structures of its two isomers and name them.
24. Give the significance of the four quantum numbers.
25. A voltaic cell is set up at 25°C with the following half cells
Al/Al3+(0.001 M) and Ni/Ni2+(0.50 M)
Write an equation for the reaction that occurs when the cell generates an electric current and determine the cell potential. [EoNi2+/Ni= -0.25V and EoAl3+/Al = – 1.66V]
26. A. Draw the structure of followings
a. H2S2O8
b. HClO4
B. a. Sulphur has a greater tendency for catenation than oxygen. Why?
b. F2 is a strong oxidizing agent than Cl2. Explain.
Question Number 27-30: 6 Marks
27. Write name, geometry and magnetic behaviour of the following complexes
a. [Pt(NH3)2ClNO2]
b. [Co(NH3)4Cl2]Cl
c. [Ni(CO)4]
28. A.An organic compound with the molecular formula C9H10O forms 2,4-DNP derivative, reduces Tollen's reagent, and undergoes Cannizzaro reaction. On vigorous oxidation, it gives 1,2-benzenedicarboxylic acid. Identify the compound.
B. How will you convert ethanal into the following compounds?
a. Butane-1,3-diol
b. But-2-enal
29. A. Transition elements exhibit variable oxidation states. Why?
B. Write the name and formula of X, Y and Z in the folloeing reaction
C2H5OH ---PCC---> X ---3Cl2/OH----> Y ---Light---> Z
C. Draw the structure of XeOF4.
30. Explain the following name reactions
A. Hell-Volhard Zelinsky Reaction
B. Wolf-Kihner Reduction
C. Aldol Condensation
