science :chemical reaction and equation CBSE ncert objective question for board 2021-22

 Class 10^th      CBSE    NCERT
Science:  chemical reaction and equation
Objective type question
For board – 2021-22

 

1.  The unbalanced chemical equation is known as ­­­­________________chemical equation.(skeletal)
2.   Displacement reaction takes place in both ________________ and ______________.(metals, non-metals)
3.   Reaction in which there is exchange of ion between the reactants is called__________________ reaction. (double displacement)
4.  Reaction in which energy is used for breaking of reactants to get simpler products is _______________ reaction. (endothermic)
5. Reaction in which heat is released with the product is called _____________ reaction. (exothermic)
6. Reaction in which precipitate substance is formed as their product then the reaction is called ____________ reaction. (precipitation)
7.  Adding of oxygen or removal of hydrogen from any substance is called ___________. (oxidation)
8. Removal of oxygen or addition of hydrogen from any substance is called ___________. (reduction)
9. When metal come in contact with air, moisture, acids etc. it gets Coted with layer of unwanted substance. It is said to be ____________ and the process is called ______________. (corrode, corrosion)
10.  When fat and oil containing substance get oxidized their taste and smell changes. This process is called ____________. (rancidity)
11. There are ____________ types of endothermic reactions. (three)
12.  When heat is used in reaction then it is called _____________. (Thermolysis)
13.  When sunlight is used in reaction then it is called_____________. (photolysis)
14.  When electricity is used in reaction then it is called _____________. (electrolysis)
15.  Reaction in which single from two or more reactants it is called ______________ reaction. (composition)
16. Reaction in which single reactants is braked to give two or more products is called ______________ reaction. (decomposition)
17. Reaction in which high reactive substance displace less reactive substance from its solution is called ______________ reaction. (displacement)
18.   Reaction in which there is exchange of ion between the reactants is called _____________________ reaction. (double displacement)
19.  ____________and______________ gases are produced on heating lead nitrate. (NO₂ , O₂)
20.   PbI₂ is of _________________ color. (yellow)
21.  Formula of magnesium nitride is _____________. (Mg₃N₂)
22.    Zinc + NaOH    à _____________. (Na₂ZnO₂)
23.    _____________ will be required to identify the gas evolve when diluted HCl reacts with Zinc. ( burning spilinter)
24.  The odour of SO₂ is ______________. (pungent)
25.  The bleaching action of chlorine is ______________ reaction. (oxidation)