Advertisements
Advertisements
Question
Give scientific reasons.
While preparing dil. Sulphuric acid from concentrated conc. sulphuric acid in the laboratory the concentrated sulphuric acid is, add slowly to water with constant stirring.
Advertisements
Solution
i. This is exothermic process.
ii. if we poured conc. sulphuric acid speedily in a water. Water gets evaporated instantaneously and very large amount of heat is liberated which may cause an accident.
iii. to avoid this, and only small amount of heat is liberated at a time it added slowly to water with constant stirring
APPEARS IN
RELATED QUESTIONS
State the effect of an endothermic reaction.
State the effect of an exothermic reaction on the surroundings.
What do you observe when ammonium chloride is dissolved in water.
FILL IN THE BLANK
In a................ reaction heat energy is absorbed.
Give scientific reason.
While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.
Why energy is involved in a chemical change?
Name a nitrate which produces oxygen as the only gas.
State which type of chemical reaction proceeds with the absorption of heat energy.
State the following reaction whether heat is evolved or absorbed –
water is added to quicklime
Chemical reactions may proceed with absorption of heat. Give an example.
Give an example with a balanced equation, of the following reaction:
endothermic reaction
Select the correct answer from the options given below:
State the gaseous product formed, when
An exothermic reaction takes place between ammonia and neutral gas.
Classify the following reaction into Exothermic and Endothermic reactions.
Magnesium ribbon when burned in air, it forms magnesium oxide.
Assertion: A drop of petrol when touched with finger gives a chill feeling.
Reason: The above phenomenon is an endothermic one.
Match the following:
| Colum I | Column II | ||
| 1. | Alloying | a. | Exothermic change |
| 2. | Crystallization | b. | Periodic change |
| 3. | Soap powder + water | c. | Mixing of molten solids |
| 4. | Seasonal changes | d. | Pure solid |
Give scientific reasons.
While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.
Give scientific reasons.
While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.
Give scientific reason.
While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.
Give scientific reason.
While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.
