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प्रश्न
Select the chemical changes from the following list of changes
Butter turning rancid
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उत्तर
Butter turning rancid is a CHEMICAL change as composition changes, a new substance with new properties is formed, irreversible and permanent change.
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संबंधित प्रश्न
Tick the most appropriate answer.
5. Photosynthesis requires
- heat energy.
- wind energy
- sunlight.
- sound energy
Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.
State the conclusions which can be drawn, to represent photosynthesis as a physical or a chemical change.
Fill in the blank with the appropriate word of the statement given below:
Germination of seeds is considered a __________ change.
Fill in the blanks with the appropriate words of the statement given below:
Heating a piece of iron is considered a __________ change while heating a piece of coal [carbon] is considered a ___________ change.
Name the following:
The type of change physical or chemical involved – ‘when a substance undergoes a change in state, colour or size’.
Potassium chloride is added to water and stirred. A salt solution is obtained, which is then boiled, leaving behind a residue.
- Is the above change physical or chemical?
- Name the residue which remains behind after the salt solution is boiled.
- Is the change reversible or not reversible?
- Are the composition and properties of the original substance altered?
- Give a reason why the above experimentation would not be possible if calcium carbonate was taken in place of potassium chloride.
Select the chemical changes from the following list of changes
Respiration in mammals.
State whether the following statement is true or false:
Stretching of rubber bands is not a physical change.
Match the items of Column I with the items of Column II.
| Column I | Column II | ||
| (a) | Large crystals | (i) | Turns lime water into milky |
| (b) | Depositing a layer of zinc on iron | (ii) | Physical change |
| (c) | Souring of milk | (iii) | Rust |
| (d) | Carbon dioxide | (iv) | Sugar candy (Mishri) |
| (e) | Iron oxide | (v) | Chemical change |
| (f) | Dissolving common salt in water | (vi) | Galvanisation |
Grinding of wheat grain changes its size. It is a ____________ change.
