Winter Vacation Homework 2015-16
Class – VIII
Chemistry
Worksheet 1
1. Balance the following equations --------------------i)
Zn + NaOH  Na2ZnO2 + H2
ii)
Pb(NO3)2  PbO + NO2 + O2
iii)
Mg + SO2  MgO + S
iv)
NH3+ O2  H2O + N2
v)
Fe + HCl  FeCl2 + H2
2. Differentiate between the following ----------------i)
Oxidation and Reduction
ii)
Cation and Anion
iii)
Acid and Base
iv)
Diamond and Graphite
v)
Combination reaction and decomposition reaction
3. Make a 10-15 pages project on ‘Metals and Non-metals and their applications’ in a
project file. Paste the samples or pictures also.
4. Learn Valency chart and derive 20 Chemical formulae from your syllabus in a
separate middle page of a file.
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Winter Vacation Homework 2015-16
Class – VIII
Chemistry
Worksheet 2
1. Balance at least 15 chemical equations from chapters 4 and 5.
2. Balance the following equations and also indicate the type of reactions taking place------(Catalytic, Thermal Decomposition, Combination, Simple Dispalcement, Double
Decomposition, Reversible, Thermal dissociation)
∆
i)
N2O4
NO2
ii)
Pb(NO3)2 + HCl
PbCl2 + HNO3
iii)
HNO3
H2O + NO2 + O2
Pt
iv)
NH3 + O2
NO + H2Os
700 – 8000C
3. Write the chemical formulae for the following compounds----------i)
Calcium Nitride
ii)
Aluminium Sulphate’
iii)
Sodium Bromide
iv)
Magnesium Chloride
v)
Lead (II) Nitrate
vi)
Silver(I) Oxide
vii)
Mercuric oxide
viii) Potassium dichromate
ix)
Copper Suphide
x)
Sulphuric Acid
4. Give two uses of the following ---------------------i)
Hydrogen
iv) Oxygen
ii)
Acids
v) Base
iii)
Nitrogen
5. An element has 5 protons and 6 neutrons in its nucleus. Calculate its atomic number and mass
number. Name the element state its valency. Write the formulae of its nitrate and chloride.
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Winter Vacation Homework 2015-16
Class – VIII
Chemistry
Worksheet 3
1. Write the formulae of following compounds ------i) Calcium Nitrate
ii) Sodium Carbonate
iv) Potassium oxide
v) Acetic Acid
vii) Zinc Sulphide
viii) Sulphuric Acid
x) Magnesium bisulphate
iii) Sodium Suphate
vi) Ammonium Chloride
ix) Silver Nitrate
2. Complete and balance the following chemical equations ----------i)
Ca
+
ii) CH4
+
iii) C
+
(red hot Coke)
iv) Mg
+
v) Na + H2O 
vi) KClO3 
H2SO4 
O2 
H2O 
steam
H2O 
3. Name the following in the given equation--------------ZnO + C  Zn + CO
a. The substance oxidised.
c. The oxidising agent
b. The substance reduced.
d. The reducing agent.
4. State the type of change in the following ---------i)
iii)
Rusting of iron
Growing of a plant
iv)
Water Cycle
ii)
iv)
Burning of Candle
Falling of leaves from trees
5. Complete the table pertaining to the long form of the periodic table-------------Element
Atomic
Number
Hydrogen
Electronic
Configuration
Mass
No.
1
Neutrons
6
Oxygen
Sulphur
Chlorine
Calcium
16
32
35
20
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Metallic/ Non Valency
–Metallic