Answers are given in the end-
1.Identify oxidation half reaction , reduction half reaction , oxidant ( oxidizing agent ) and reductant ( Reducing agent ) in the reaction given below- Zn + CuSO4 –> Cu + ZnSO4
2.Define oxidation and reduction.
3. What is the difference between combination and decomposition reaction?
4.What is the difference between displacement and double displacement reaction?
5.What is exothermic reaction ?
6. What are the photochemical reactions?
Answers–>
1.Oxidation half reaction Zn —> Zn2+ + 2e–
Reduction half reaction Cu2+ + 2e– —> Cu
Oxidant CuSO4 or Cu2+
Reductant Zn
2. Removal of electron or hydrogen and addition of oxygen is called oxidation whereas Removal of oxygen or addition of electron or hydrogen called reduction.
3.The reaction in which two or more reactants to form one product is called combination reaction.
C + O2 –> CO2
The reaction in which one reactants is broken into two or more products is called decomposition reaction.
CaCO3 —> CaO + CO2
4.The reaction in which less reactive element from its compound is displaced from more reactive element is called displacement.
Zn + CuSO4 –> Cu + ZnSO4
Whereas cations or anions of two compound are displaced by each other.
BaCl2 + Na2SO4 –> BaSO4 + 2 NaCl
5. The reactions in which heat is liberated is called exothermic reaction.
Example- Formation of ammonia gas N2 + 3 H2 –> 2 NH3 + Heat
or Burning of magnesium wire 2 Mg + O2 –> 2 MgO + Heat + Light
6.The reactions which occur only in presence of light are called photochemical reaction.
example- Photosynthesis 6CO2 + H2O (Sun Light)–> C6H12O6 + O2
or H2 + Br2 (Sun Light)–> HBr
CHEMIGOD 