Question

While diluting an acid, it is recommended that the acid should be added to water.

Hint:

Always add acid to water to avoid splashing due to heat.

Answer 1

Why Acid Should Be Added to Water While Diluting:

While diluting an acid, it is always recommended that acid should be added slowly to water and not water to acid. This safety rule is followed because the dilution of an acid is a highly exothermic reaction, meaning it releases a large amount of heat.

Detailed Explanation:

1. Heat Production:
When concentrated acid is mixed with water, a significant amount of heat is produced. If water is added to acid, the small amount of water may boil rapidly due to sudden heating and cause the acid to splash out violently.

2. Risk of Splashes and Burns:
Acid splashes can cause serious burns to skin, eyes, and clothes. Adding water to concentrated acid increases the risk of sudden boiling and splattering.

3. Safe Dilution Method:
When acid is added slowly to a large amount of water with constant stirring, the heat produced gets absorbed by the water gradually. This prevents sudden temperature rise and reduces the chances of splashing.

4. Laboratory Safety Rule:
The safety rule followed in laboratories is:
“Always add acid to water, never water to acid.”

Conclusion:
Acid is added to water during dilution because the reaction is highly exothermic. Adding acid slowly to water ensures safe mixing, prevents splashing, and avoids serious accidents.