What is the difference between concentrated and dilute acids? When diluting acids, why do we always add the acid slowly to the water?
Answer (1)
In chemistry, the terms 'concentrated' and 'dilute' are used to describe the amount of acid dissolved in a given volume of solvent (usually water).
Concentrated Acid: A concentrated acid contains a large amount of acid relative to the amount of water. This means there are more acid molecules in the solution, making it stronger and more reactive. For example, concentrated hydrochloric acid might contain about 37% hydrogen chloride.
Dilute Acid: A dilute acid, on the other hand, contains a smaller amount of acid in relation to the amount of water. There are fewer acid molecules in a dilute solution, making it weaker and less reactive. For example, if you dilute the concentrated hydrochloric acid with additional water, this lowers the percentage of hydrogen chloride in the solution.
When diluting acids, it is essential to add the acid slowly to water, rather than the other way around. This is due to several safety reasons:
Heat Release: Mixing acid with water is often an exothermic reaction, meaning it releases heat. Adding acid to water allows the heat to dissipate quickly in the large volume of water, reducing the risk of splashing concentrated acid.
Prevention of Splashes: If you add water to a concentrated acid, the reaction can occur rapidly, causing splattering and potentially dangerous splashes of the acid.
Controlled Reaction: By adding acid to water slowly, you control the rate of the dilution reaction, minimizing the risk of an uncontrollable and potentially dangerous reaction.
Always remember the safety phrase: 'Add acid to water, like you ought'er.' This helps ensure safety in the laboratory or any chemical handling scenario.
