Wednesday, March 16, 2011

chemical-reactions-and-equations


JSUNILTUTORIA
PANJABI COLONY GALI NO
CHEMISTRY X
Chemical Reaction and Equations

  1. Respiration is:
(a) Endothermic reaction
(b)Exothermic reaction
(c) Addition reaction
(d) None




  1. Photolysis is:
(a) Decomposition
(b) Addition
(c) Displacement
(d) Oxidation




  1. Fe2O3 + 3CO → 2Fe + 3CO2, which is reducing agent in the above reacton:
(a)  Fe2O3
(b)  CO
(c)  Fe
(d)  CO2




  1. What are the conditions for rusting of an iron article:
(a) Presence of air
(b) Presence of moisture
(c) Both
(d) None




  1. Plaster of Paris is
(a) 2CaSO4.H2O
(b) CaSO41/2H2O
(c) Both
(d) None




  1. Oxidation reaction is a chemical process in which a substance:
(a) Gains hydrogen
(b) Gains oxygen
(c) Gains chlorine
(d) None




  1. Hydration means:
(a) addition of hydrogen
(b) addition of hydrogen chloride
(c) addition of sulphuric acid
(d) addition of water




  1. The decomposition of CaCO3 is
(a) an endothermic reaction
(b) an exothermic reaction
(c) an photolysis reaction
(d) None




  1. Hydrogenation means :
(a) addition of hydrogen
(b) addition of hydrogen chloride
(c) addition of sulphuric acid
(d) addition of water




  1. Al(OH)3 + HCl → AlCl3 + _______
(a) H2O
(b) H2
(c) AlCl3
(d) None




  1. A solution of substance X is used for white washing. What is X:
(a) CaO
(b) Ca(OH)2
(c) CaCO3
(d) CaCl2




  1. What happens when dil HCl is added to iron filing:
(a) Hydrogen gas and iron chloride are produced
(b) Cl2 gas and Iron hydroxide are produced
(c) No reaction takes place
(d)Iron salt and water is produced




  1. Fe2O3 + 2Al → Al2O3 + 2Fe
The above reaction is an example of a:
(a) Combination reaction
(b) Double displacement reaction
(c) Decomposition reaction
(d) displacement reaction




  1. Nitrogen gas is used by chips manufacturer since:
(a) Nitrogen is an oxidizing agent
(b) Nitrogen gas is a reducing agent
(c) Nitrogen is an antioxidant
(d) None.




  1. AB + CD → AD + CB
The above reaction is an example of
(a) Displacement
(b) Double displacement
(c) combination
(d) oxidation




  1. Which of the following are the characteristics of a chemical reaction:
(a)  Evolution of gas
(b) formation of precipitate
(c) change in color
(d) all




  1. CH4 + O2  → CO2 + ________
(a) Hydrogen
(b) water
(c) CO
(d) none




  1. A balance chemical equation has :
(a) an equal number of atom
(b) an equal number of mass
(c) an equal number of protons
(d) an equal number of electrons






  1. In chemical reaction:
(a) only electron takes part
(b) only protons take part
(c) only neutrons take part
(d) none




  1. Na is placed in kerosene oil since:
(a) Na is soft
(b) Na is highly inflammable
(c) Na is metal
(d) none




  1. The properties of product in a chemical reaction is
(a) same as that of reactant
(b) different as that of reactant
(c) Both
(d) none




  1. Rust is chemically defined as:
(a) Fe2O3.xH2O
(b) Fe3O4.xH2O
(c)  Fe2O3.2H2O
(d)  Fe3O4.xH2O




  1. Food items can be preserved for longer time when kept in a refrigerator since:
(a)  The reduction process starts in              refrigerator
(b) the oxidation process starts in refrigerator
(c) At lower temperature oxidation process gets slowed
(d) None





  1. When sodium reacts with Cl2, the molecular formula of product in Balance equation is
(a) 2NaCl
(b) NaCl
(c) 3NaCl
(d) NaCl2




  1. We apply paint on iron article to
(a) Prevent from corrosion
(b) improve the hardness
(c) make it attractive
(d) None



Answers

1
(a) Endothermic reaction
14
(c) Nitrogen is an antioxidant
2
(a) Decomposition
15
(b) Double displacement
3
(b)  CO
16
(d) all
4
(c) Both
17
(b) water
5
(c) Both
18
(a) an equal number of atom
6
(b) Gains oxygen
19
(a) only electron takes part
7
(d) addition of water
20
(b) Na is highly inflammable
8
(a) an endothermic reaction
21
(b) different as that of reactant
9
(a) addition of hydrogen
22
(a) Fe2O3.xH2O
10
(a) H2O
23
(c) At lower temperature oxidation process gets slowed
11
(a) CaO
24
(a) 2NaCl
12
(a) Hydrogen gas and iron chloride are produced
25
(a) Prevent from corrosion
13
(d) displacement reaction



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