Advertisements
Advertisements
प्रश्न
Give the main experimental points only to demonstrate that candle-gains weight on burning.
Advertisements
उत्तर
Candle gains weight on burning
1. Weight: The complete apparatus as shown above which includes -
- Unlit candle ‘A’.
- U tube ‘B’ containing anhydrous CaCl2.
- Conical flask ‘C’ containing cone. KOH soln.
Total wt. = a gms.
The candle ‘A’ is then lit and the products obtained on burning are allowed to be absorbed in U tube ‘B’ and conical flask ‘C’.
2. Re-weigh: The complete apparatus as shown above after the candle has burnt – for a known period of time.
Total wt. = b gms.
Result:
- ‘b’ gms. is greater than ‘a’ gms.
- weight of apparatus after absorbtion
- of products is greater than the original weight of the apparatus.
Conclusion: Candle gains weight due to mass of oxygen of the air which has combined with ‘carbon’ and ‘hydrogen’ of the candle [CxHy] producing .
- Water vapour [absorbed by anhydrous CaCl2]
- Carbon dioxide [absorbed by cone. KOH soln].
APPEARS IN
संबंधित प्रश्न
Write fully balanced equation for the following :
MgO + H2O →
What is rusting?
State two most important conditions for rusting.
In the laboratory preparation of oxygen from hydrogen peroxide answer the following:
Draw a neat labelled diagram for the method used in the above preparation.
In the laboratory preparation of oxygen from hydrogen peroxide answer the following:
State the word equation for the reaction involving the above preparation of oxygen.
Distinguish between:
Combustion and Respiration
Give the main experimental points only to demonstrate that magnesium.
Give reason for the following:
Acid rain has caused damage to heritage structures such as the Taj Mahal.
What is meant by burning?
Match the following
| 1. | Burning of meteors | a. | Exosphere |
| 2. | Weather change | b. | Stratosphere |
| 3. | Lowest temperature | c. | Mesosphere |
| 4. | Ozone layer | d. | Troposphere |
