Advertisements
Advertisements
प्रश्न
What is the difference between dissolution of sugar and burning of sugar ?
Advertisements
उत्तर
1. Dissolution of sugar:
- When sugar is dissolved in water it disappears. It we taste the solution, the sugar is still present in dissolved form.
- If water is evaporated we get back the sugar.
- So it is a physical and reversible change.
2. Burning of sugar:
- Fire activates a chemical reaction between sugar and oxygen. The oxygen in the air reacts with the sugar as the chemical bonds broke.
- Energy is released in the form of smoke.
- So, burning a sugar is a chemical change.
APPEARS IN
संबंधित प्रश्न
Classify the following as chemical or physical change:
Dissolving common salt in water.
Tick the most appropriate answer.
4. Chemical changes involve
- change in shape.
- change in size.
- change in molecular composition.
- none of these
Ripening of fruits is a desirable change.
State whether the following is physical or chemical changes.
photosynthesis —
Given reason:
Burning of paper is a chemical change.
Fill in the blank with the correct word of the statement given below:
Sublimation involves a __________ change.
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.
A change in which matter undergoes a change but the total mass of the substance is unaltered is a ______ change.
You are given some candle wax. Can you make a candle doll from it? What kind of change is this?
Physical Change: Boiling::Chemical Change: ______.
