CHEMISTRY MODEL QUESTION PAPER

SET 5

1. Complete the following table
(3)
Volume at STP No. of moles Mass in gms
100 ml CO2 ------ ------
------ 0.5 mole of N2 -------
-------- ---------- 20 g of CH4
2. Emission spectrum or absorption spectrum is used as a finger print of an atom.
a. Give one difference between absorption and emission spectrum (1)
Yellow light emitted from a Na lamp has a wavelength ( λ ) of 550nm. Calculate the frequency
and waves of yellow light (2)
b. Illustrate Pauli’s exclusion principle with electronic configuration of ‘N’ atom. (2)
3. The hybridization of carbon in ethane,ethane and ethyne are different.
a. What is hybridization?
b. What are the different hybridization of carbon in ethane,ethane and ethyne (3)
4. Quantitative measure of tendency of element to lose electron is Ionization energy
a. Ionization energy of Nitrogen is greater than Oxygen. Why? (2)
b. Ionization energy decreases regularly down the group of periodic table.Why ?
5. VSEPR theory is used to determine the shape of molecule
a. Write the no. of bond pairs of electrons and lone pair electrons in NH3 molecule. (2)
b. o-nitrophenol is steam volatile where as p-nitrophenol is not. Justify your
Answer giving reason. (1)
6. The volume of air bubbles gradually increases as it rises up from the bottom of An aquarium.
a. Name and state the gas law that explains this phenomena. (2)
b.Can oxygen exist as a gas at -273.15º C. Write the significance of this temperature (2)
7 a. Calculate the eathalpy of formation of CO from C using the following data.
i) C + O2 􀃠 CO2, ΔH = -393.5 kj/mol.
ii) CO + ½ O2 􀃠 CO2, ΔH = 283 kj/mol (2)
8. Select the odd one out of the following set
a. Temparature, Pressure, Density (intensive property)
b. Human body , earth , water in a closed vessel (type of system)
c. Internal energy, work, enthalpy, entropy (state function) (3)
9. A redox reaction involves a simultaneous oxidation half reaction and a reduction half reaction
a. Write the electronic concept of oxidation and reduction: (1)
b. Identify the oxidising Agent and reducing agent in the following reaction.
Zn + CuSO4 􀃠 ZnSO4 + Cu (2)
10. A sample of hard water was found to lose its hardness on boiling. Explain the type of hardness.
(3)
11. a, K2CO3 cannot be prepared by solvay process. Why ?
(2)
b. A solution of Na2CO3 is alkaline. Why ? (2)
12. a, Graphite conduct electricity while diamond doesn’t Explain why?
(2)
b. Distinguish between silicons and silicates (2)
13. Hydrates of boron is called boranes. Discuss the structure and preparation of Diborane
(3)
14. Give the IUPAC name of
a. CH3 - CH2 – CH2 - CH2 – CH2 – COOH
b CH3 – CH – CH = CH2
CH3 (2)
15. Lassaignes’s test used to detect the N,P,S and X in organic compound. Discuss
The chemistry of Lassaigne’s test .
16. Addition of HBr to 3-methyl -1-butene yields a mixture of two alkyl bromides.
i. Write the structure of IUPAC name of those compounds. (2)
ii. Which is the major product in the reaction. Why ? (2)
17. Bayer’s test is used to detect unsaturation in organic compound ?
a. What is Bayer’s Reagent (1)
b. What is the product formed when ethylene treated with Bacyer’s regent. (2)