Kerala Plus One Model Question Paper Chemistry

SAMPLE
PAPER

FIRST YEAR HIGHER SECONDARY EXAMINATION

Part – III Time: 2 Hours

CHEMISTRY Cool-off time: 20 Minutes

Maximum: 60 Scores

Answer any 4 questions from 1 to 5.Each carries 1 score (5×1=5)

1. Which of the following orbital is possible
(a)1p (b)2s (c)3f (d)2d
2. The number of moles in 36g H2O is …………
3. The oxidation number of Mn in KMnO4 is…………………
4. Kjeldahl’s method is used to estimate the presence of ……. In an organic compound
5. What is the product obtained when ethyne is passed through red hot tube undergo cyclic
polymerization?
Answer any 8 questions from 6 to 15. Each carries 2 scores (8×2=16)
6. Write the empirical formula of
(a)C12H22O11
(b)C6H6
7. Cation size is smaller than the corresponding atom. Justify
8. What are isoelectronic species? Identify which ion is not an isoelectronic species
(F─, Mg2+ , K+, O2─ )
9 Fill in the box
Molecule Geometry Bond angle
CH4 Tetrahedral 109°28′
BeCl2 ……………. 180°
BF3 Trigonal planar ………………….

10. Why He2 molecule does not exist?
11. Sketch the enthalpy diagram for an edothermic reaction

12. Assign the oxidation number and identify the type of the redox reaction given below
2H2O 2H2 + O2

13. Identify the oxidant and reductant in the following reaction
2Cu2O(s) + Cu2S(s) 6Cu(s) + SO2(g)
14. Write the IUPAC name of the following compound
(a) CH3COCH2CH2CH2COOH
(b) CH≡≡≡C─CH2─CH─CH2─CH3

CH3
15.Cyclopentadienyl anion is aromatic. Justify your answer

Answer any 8 questions from 16 to 26. Each carries 3 marks (8×3=24)

16.(a) Carbon burns in oxygen to form CO and CO2. Which law is illustrated here (1)
(b) State the Law (2)
17.(a) Which series of hydrogen spectrum lies the visible region (1)
(b) Calculate the wavelength of first line in the Lyman series (2)
18. Draw the MO diagram of N2 molecule .Find its bond order (3)
19. Which out of NH3 and NF3 has higher dipole moment and Why? (3)
20.(a) Categorize the following into Lewis acid and Lewis base
OH─, F─, H+, BCl3 (2)
(b) What is the conjugate base for HF (1)
21.(a)Addition of CH3COO- ions to CH3COOH decreases the concentration of H+ ions.
Account for this statement. (1)
(b) Examine the chemical equilibrium
4NH3 (g) + 5 O2(g ) ↔ 4NO(g) + 6H2O(l) (2)
Write the expression for equilibrium constant (Kc ) (2)
22. What is meant by spontaneous processes? Give the criterion of spontaneity in terms of ∆G
for a process taking place at constant temperature and pressure (3)
23. Explain different types of structural isomerism exhibited by an organic compounds (3)
24. CH3─CH═CH2+HBr→A+B. Identify A and B. Which law is obeyed here (3)
25. Complete the following reactions
(a) OH

+ Zn dust ………………………….. (1)

Red hot Fe tube
(b) 3CH≡CH …………………………… (1)
873K

Dry ether
(c)2CH3─I +2Na …………………………….. (1)

26. (a) State Heisenberg Uncertainty Principle (1)
(b)A microscope using suitable photons is employed to locate an electron in an atom
within a distance of 0.1A°.What is the uncertainty involved in the measurement of its
velocity? (2)
Answer any 4 questions from 27 to 31. Each carries 4 marks (4×4═16)
27.(a) What are the observations made by Rutherford during his ἁ- ray scattering Experiment(3)
(b) Give any two demerits of Rutherford’s atom model (1)
28. (a)Why electron gain enthalpy of Chlorine is greater than that of Fluorine (1)
(b) How does ionisaton enthalpy varies along a period and group? (2)
(3)Name a scale which is used to measure electro negativity (1)
29.(a) State the first law of thermodynamics and write its mathematical expression. (2)
(b)Define Gibb’s energy (1)
(c) Give the relationship between Gibb’s energy change (∆G) and entropy change(∆S) of a
reaction (1)
30. (a) State Lechatelier’s Principle (1)
(b) What is the effect of temperature and pressure on the equilibrium?
N2+3H2↔2NH3 ∆H ═ ─393.5KJ (2)
31.(a) What are the different methods of purification of organic compounds (2)
(b) Explain any one method (2)