Unit no 06 Chemical Reaction.
Q1. Define Chemical reactions?
Ans. A process during which a substance
changes into new substance with
different composition is called chemical
reaction.
Q2. Define reactants?
Ans: The thing which take part in a chemical
reaction are called reactants.
Q3. Define products?
Ans: The new things which are produced as a
result of chemical reaction are called
products.
Q4 Write down application of chemical reaction?
Burning.
Heat produced during the burning of fossil in our kitchen is used to cook food.
Respiration.
Energy produced as a result of respiration is used to perform all body function.
Photosynthesis.
During photosynthesis plant their food (glucose)
Q.5Define chemical equation?
Chemical equation is the representation of chemical reaction in form of symbol and formula.
Q 6.State law of conservation of mass (matter)?
,During a chemical reaction mass is neither created nor destroyed but it changes from one to
another.
Q7. Write down working rules for balancing the
chemical equation?
Rules:
i) Write the unbalanced equation and count
the number of atoms of each element on both
sides of the arrow
ii) Start with one element at a time.
iii) Multiply the symbols or formula with suitable
integers (2, 3, 4, 5) etc. on that side of
the equation where the number of atoms of a
particular element is less, and try to
balance the atoms on both sides of the
equation. Start multiplying with relatively
small numbers.
iv) Repeat the process for all the elements
one by one.
v) Balance the diatomic molecules like
H₂, N₂, O₂, Cl₂ etc at the end.
Q8. Define balanced and unbalanced chemical
equation?
Ans. Balanced Chemical Equation:
A chemical equation in which the number of
atoms of each element on both sides of the
equation is equal is called a balanced
, chemical equation.
Example:
S + O₂ → SO₂
Unbalanced Chemical Equation:
A chemical equation in which the number of
atoms of each element on both sides of the
equation is not equal is called an unbalanced
chemical equation.
Example:
Na + Cl → NaCl
Q9. Who put forward the law of conservation of
mass?
Ans. A French chemist, Antoine Lavoisier, in 1788.
Q10. Define combination reaction?
Ans. The chemical combination of two or more
substances to form one compound is called
combination reaction.
Q11. Define decomposition reaction?
Ans. The chemical reaction in which a substance
splits into two or more simpler substances
is called decomposition reactions
Example:
CaCO₃ → CaO + CO₂
Q12. Define displacement reaction?
Ans. A displacement reaction involves the replacement
Q1. Define Chemical reactions?
Ans. A process during which a substance
changes into new substance with
different composition is called chemical
reaction.
Q2. Define reactants?
Ans: The thing which take part in a chemical
reaction are called reactants.
Q3. Define products?
Ans: The new things which are produced as a
result of chemical reaction are called
products.
Q4 Write down application of chemical reaction?
Burning.
Heat produced during the burning of fossil in our kitchen is used to cook food.
Respiration.
Energy produced as a result of respiration is used to perform all body function.
Photosynthesis.
During photosynthesis plant their food (glucose)
Q.5Define chemical equation?
Chemical equation is the representation of chemical reaction in form of symbol and formula.
Q 6.State law of conservation of mass (matter)?
,During a chemical reaction mass is neither created nor destroyed but it changes from one to
another.
Q7. Write down working rules for balancing the
chemical equation?
Rules:
i) Write the unbalanced equation and count
the number of atoms of each element on both
sides of the arrow
ii) Start with one element at a time.
iii) Multiply the symbols or formula with suitable
integers (2, 3, 4, 5) etc. on that side of
the equation where the number of atoms of a
particular element is less, and try to
balance the atoms on both sides of the
equation. Start multiplying with relatively
small numbers.
iv) Repeat the process for all the elements
one by one.
v) Balance the diatomic molecules like
H₂, N₂, O₂, Cl₂ etc at the end.
Q8. Define balanced and unbalanced chemical
equation?
Ans. Balanced Chemical Equation:
A chemical equation in which the number of
atoms of each element on both sides of the
equation is equal is called a balanced
, chemical equation.
Example:
S + O₂ → SO₂
Unbalanced Chemical Equation:
A chemical equation in which the number of
atoms of each element on both sides of the
equation is not equal is called an unbalanced
chemical equation.
Example:
Na + Cl → NaCl
Q9. Who put forward the law of conservation of
mass?
Ans. A French chemist, Antoine Lavoisier, in 1788.
Q10. Define combination reaction?
Ans. The chemical combination of two or more
substances to form one compound is called
combination reaction.
Q11. Define decomposition reaction?
Ans. The chemical reaction in which a substance
splits into two or more simpler substances
is called decomposition reactions
Example:
CaCO₃ → CaO + CO₂
Q12. Define displacement reaction?
Ans. A displacement reaction involves the replacement
