Advertisements
Advertisements
Question
What is the difference between dissolution of sugar and burning of sugar ?
Solution
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
RELATED QUESTIONS
Explain the following giving an example.
Pure substance
State whether the following is physical or chemical changes.
glowing of a bulb -
State whether the following is physical or chemical changes.
respiration in living beings —
Write true or false
Rusting of iron is a chemical change.
What is a physical change ? Give two examples of physical changes.
Which of the following are chemical changes ?
- decaying of wood
- burning of wood
- sawing of wood
- hammering of nail into wood
Name the following.
The gaseous product of the chemical change which takes place during respiration in living organisms.
Match the following
| Sr. No. | A | B | C |
| 1. | Melting | Change of state from liquid to solid | Ticking of clock |
| 2. | Condensation | Change of state from liquid to gas | Formation of ice cube |
| 3. | Evaporation | Change of state from solid to liquid | Collecting flowers |
| 4. | Freezing | Change of state from gas to liquid | Ice cube to water |
| 5. | Periodic change | Occurs at irregular time intervals | Water to steam |
| 6. | Non-periodic change | Occurs at regular time intervals | Steam to water drops |
Grinding of wheat grain changes its size. It is a ____________ change.
If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance, called rust.
Do you think rust is different from iron?
