CHEMISTRY
SCIENCE Paper – 2
Duration: 2 hours
Total marks: 80
Section I is compulsory. Attempt any four questions from Section II
The intended marks for questions or parts of questions are given in brackets [ ].
Section I (40 marks)
Question 1
A. Choose the correct answer
1. The proton was discovered by………………….
a) John Dalton
b) Goldstein
c) Rutherford
d)Niles Bohr
2. Number valence electrons in O2- is:
a) 6
b) 8
c) 10
d) 4
3. ……………………… is an alkaline earth metal
a)Sodium
b)Strontium
c)Scandium
d)Zirconium
4. Reacting with water, an active metal produces
a)oxygen
b)nitric acid
c)a base
d)none of these
5. ………………………. metals does not give hydrogen with acids
a) Iron
b) zinc
c) copper
d) lead
B. Fill in the blank
1. Metals like ………., ……………and ………..give H2with steam
2. A metal oxide that is reduced by hydrogen is……………..
3. Relative atomic mass of a light element up to calcium is approximately………….its atomic number.
4. When electrical discharge of 10,000volts is passed through gases at very low pressure……….are
produced.
5. A reactive in which oxidation and reduction take place simultaneously is known as………………..
C. Match the following
1. Highly reactive elements
-
Alkaline earth metal
2. Radioactive elements
-
Alkali metals
3. Nonreactive elements
-
Halogens
4. Elements short by 1 electron in octel
-
Noble gas
5. Elements with 2 electrons in the outer most orbit
-
Actinide
D. Name or state the following with reference to the elements of the periodic table.
1. Metalloid in period 3.
2. Group whose elements have zero valency.
3. Non –metallic element present in Periods 3 of groups 15 and 16.
4. Alkali metal in period that dissolves in water giving a strong alkali.
5.
Alkaline earth metal in Period 3.
E. Write balanced equations for the following
1. Iron reacts with dil HCl
2. Zinc reacts with caustic soda solution
3. Magnesium with steam
4. Sodium with water
5. Aluminum reacts with fused sodium hydroxide
F. Complete and balance the following reaction
1.
Al + H2SO4
--------------+---------------
2.
Zn + HCl
--------------+---------------
3.
Al + KOH +H2O
4.
Fe + HCl
5.
Mg +H2O
--------------+----------------------------+----------------------------+---------------
G. Select the odd one and justify your answer
1. Fe, Zn, Mg and Na
2. SO2, H2S, NH3 and CO3
3. Fe, Zn, Cu and Mg
4. Fe, Pb, Al and Zn
5. Al, Si, Te and As
H. State, whether the substances have been oxidized or reduced
1. 2Mg +O2
2. 2NH3 + 3 Cl2
3. H2S + Cl
4. PbO +CO
5. ZnO + C
2MgO
N2+6 HCl
2HCl + S
Pb +CO2
Zn +CO
Section II (40 marks)
Attempt any four questions from this Section
Question 2
1. Write the difference between oxidation and reduction
[2]
2.
[2]
Which metal is preferred for collecting hydrogen from:
a) Cold water
b) hot water
Write balanced equation for each case
3. For the laboratory preparation of hydrogen , give the following
a) materials used b) method of collecting
c) chemical equation
[4]
d) fully-labeled diagram
4. Name the impurities present in hydrogen prepared in the laboratory and how it is removed
[2]
Question 3
1. Observe the following and recommend the measures to control :
a) Carbon monoxide emission
[4]
b)SOx emission
2. Explain the formation of ozone in the atmosphere
[2]
3. What is the cause of acid rain? Give any two impacts of acid rain
[2]
4. What is smog? State its damaging effect?
[2]
Question 4
1. State the defects of Mendeleev’s periodic table
[2]
2. State the Merits and demerits of modern periodic table
[2]
3. What is the name given to group 2 elements , and describe its characteristics
[4]
4. What are the different types of elements and describe the main characteristics of each?
[2]
Question 5
1. State major drawback of Rutherford’s atomic model
[2]
2. Draw orbit structure and electron dot diagrams of NaCl, and CaO
[2]
3. What are isotopes? With reference to which fundamental particle do Isotopes differ? Give two
[4]
uses of Isotopes
4. Explain covalent and ionic bond with one example
[2]
Question 6
1.
Draw a diagram representing the atomic structures of the following
a)
Sodium atom
2.
Why should an equation to be balanced?
[2]
3.
Calculate the relative molecular masses of
[2]
a)CH3COONa
b) Potassium c) Calcium
[2]
d) Argon
b)CuSO4.5H2O
4. Explain the discovery of nucleus with diagram
[4]