Chemistry
Assertion - Heating of iron with sulphur is a physical change.
Reason - A new substance, iron sulphide is formed, when iron and sulphur are heated together.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Phy & Chem Changes
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Answer
A is false but R is true.
Reason — A is false as when iron is heated with sulphur, they chemically react. A new substance is formed, so it is a chemical change, not a physical one.
R is true as when iron and sulphur are heated together, iron sulphide is formed. This new substance has different properties from iron and sulphur.
Therefore, A is false but R is true is the correct option.
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Related Questions
Assertion - Naphthalene balls disappear from the cupboard after sometime.
Reason - Naphthalene balls undergo evaporation.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion - During a chemical change, new substances with entirely different properties are formed.
Reason - Bursting of a cracker is a chemical change.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Fill in the blanks
(a) A new substance is always formed in a …………… change.
(b) Melting of ice is a …………… change.
(c) When a candle burns, wax melts. Melting of wax is a …………… change.
(d) Chemical change occurs as a result of …………… between two substances.
(e) Burning of a fuel is a …………… change.
(f) Revolution of the earth around the sun is a …………… change.
(g) Growing of a seedling into a plant is a …………… change.
Write True or False against the following statements:
(a) Cutting of paper into pieces is a chemical change.
(b) Rusting of iron is a chemical change.
(c) Earthquake is a desirable change.
(d) Melting of ice is a physical change.
(e) Burning of sugar is a temporary change.