Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर १
- The preparation of dilute sulphuric acid falls into the category of an extreme exothermic process.
- During the preparation of dilute sulphuric acid, a large amount of water is taken into a glass container that is surrounded by ice. Cool it for twenty minutes. Now a small quantity of conc. H2SO4 is added slowly with stirring. Therefore, only a small amount of heat is liberated at a time. In this way, dilute sulphuric acid is prepared.
- On the other hand, in the process of dilution or conc. sulphuric acid with water, a very large amount of heat is liberated. As a result, water gets evaported instantaneously if it is poured into conc. H2SO4, which may cause an accident.
उत्तर २
- This is an exothermic reaction.
- If we quickly put concentrated sulphuric acid into water. Water evaporates instantly, liberating a tremendous amount of heat that could cause an accident.
- To avoid this, a tiny amount of heat is supplied gently to water while stirring constantly.
APPEARS IN
संबंधित प्रश्न
How will you obtain Ammonia from nitrogen.
Also give balanced equations for the reactions
State the effect of an endothermic reaction.
Identify the endothermic and exothermic reaction.
\[\ce{2KClO_{3(s)}->[\Delta] 2KCl_{(s)} + 3O2}\]
Give an example of the following chemical changes.
A photochemical reaction involving silver salt.
Give an example of the following chemical changes.
A reaction involving blue solution.
Why energy is involved in a chemical change?
What do you observe? When
Lead nitrate is heated.
Give an example of the following chemical changes.
An exothermic and an endothermic reaction involving carbon as one of the reactants.
State the following reaction whether heat is evolved or absorbed –
Two neutral gases on passage through an electric are given nitric oxide.
Complete the statement by filling in the blank with the correct word:
The element molybdenum used in the reaction of nitrogen with hydrogen at elevated temperatures is an example of a ________.
Give an example of an endothermic reaction.
Chemical reactions may proceed with absorption of heat. Give an example.
Explain the term energy changes in a chemical change or reaction.
Give an example with a balanced equation, of the following reaction:
photochemical reaction
Supply of energy may be required to initiate a reaction. State the different forms with a suitable example of reactions initiated by the supply of energy.
Complete the statement by filling in the blank with the correct word:
The reaction of hydrogen burning in oxygen to give a neutral liquid is an example of ________ reaction.
Give examples of the endothermic process.
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 a 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 slowly added to water with constant stirring.
