Previous year questions of chemistry class 10 : PYQs of chemistry class10 chapter 1st chemical reaction and equation
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Here you will get the answer to every question asked by CBSE in the examination. 
Previous year questions of chemistry class 10 chapter 1st.
Q1). State whether the equation is balanced or not:-
→H2+Cl2→2HCl
→BaCl2+Al2(SO4)3→BaSO4+AlCl3
→NaoH+HCl→NaCl+H2O
Answer - Balanced equation
- Unbalanced equation
- Balanced equation
Q2). A solution of a substance x is used for whitewashing.
→Name the substance x.
→Write the reaction of the substance X with water.
Answer - a substance x is calciumoxide (cao)
- cao + H2O → Ca(OH)2
Q3). Give 2 examples of displacement reaction.
Answer - zn + cuso4 → znso4 + cu
- Pb + cucl2 → Pbcl2 + cu
Q4). What is a balanced chemical equation?
Answer - To see this answer please scroll down.
Q5). Explain all the 5 types of reactions with 1 example.
Answer -To see this answer please scroll down.
Q6). Write one equation each for decomposition reaction.
Answer - To see this answer please scroll down.
Q7). Explain the following in terms of gain or loss of oxygen with two examples each.
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Q8). Why do we apply paint to the iron article?
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Q9). Ferrous sulphate decomposes with the evolution of a gas having a characteristic odour of burning sulphur write the chemical equation involved and the type of reaction.
(Heat)
Answer - feSO4 → fe2O3 + SO2 + SO3
It is a thermal decomposition reaction.
Q10). List two observation when this reaction takes place?
FeSO4 → Fe2O3 + SO2 + SO3