Question

9. How will you protect yourself from the heat generated while diluting a concentrated acio?
A. By adding acid to water with constant stirring.
B. By adding water to acid with constant stirring.
C. By adding water to acid followed by base.
D. By adding base to acid with constant stirring.​

Answer 1

Answer:

Option A is the correct

Explanation:

When acid is added to water for preparing the dilute acid the heat evolved is gradual and the heat is absorbed by large amount of water but in the case when water is added to the acid large amount of heat is evolved at once because the heat changes some of the water to steam explosively which splashes on us.

Answer 2

The Correct solution is Option A, By adding acid to water with constant stirring.

• Concentrated acid dilution is an exothermic process.
• When water is added to a concentrated acid, the heat produced may cause the mixture to splash out, causing burns.
• The mixture will not splash out if the acid is slowly added to water while stirring constantly.
• An exothermic process is one in which energy is released in the form of light or heat.
• As a result, rather than withdrawing energy from the environment as an endothermic reaction does, an exothermic reaction transfers energy into the environment.
• In an exothermic process, the change in enthalpy (H) is negative.
• Since the hydrogen ion in acid is so small, a huge amount of charge is concentrated in a small area, attracting the polar water molecules forcefully.
• The development of a covalent link to one of the waters, as well as a huge number of strong hydrogen bonds, makes this 'hydration' of the hydrogen ion a highly exothermic process.
• This results in a significant exothermic reaction when a strong acid is mixed with water.