Chemistry

Dilute acids

Acids are classified based upon the concentration of acids as dilute acids and concentrated acids. Dilute acids are a group of acids that contain a large amount of water. They are concentrated for minimize the amount of concentration of acid present. It prevents the risk of high-risk acids. We also concentrate on acids for storing them for daily use. They are also used in controlling many chemical reactions. In this article, we look at the meaning, properties, handling, and storage of dilute acids.

Meaning of dilute acids

The concentration of acid can be varied by simply adding water. In chemistry, the concentration of an acid depends upon the number of hydrogen ions present in the substance. Based on the concentration of acid, they can be classified into two categories:

Concentrated acid: Concentrated acid is an acid that is either in pure form or is having a high concentration of acid content.
Diluted acid: Diluted acids are having a high concentration of water than the concentration of acid itself.

Examples of dilute acids

The most commonly used dilute acid is hydrochloric acid. Hydrochloric acid in its concentrated form is very corrosive and hence cannot be used for daily purposes. Dilute hydrochloric acid is used for daily uses such as cleaning surfaces, medical treatments, production of batteries, etc. You can read our article on 50 uses of acids for more details.

Dilute acetic acid is a commonly used acid in our homes. It is used as a cleaning agent, in salads, in chemical synthesis, etc. Vinegar is about 4% dilute acetic acid. You can read about our article on 15 acids and bases in our homes for more details.

vinegar-example of dilute acid — Vinegar is a dilute acid made from concentrated acetic acid.

Strong acids like citric acids, sulfuric acids are generally used in their diluted form to reduce the risk involved in handling them. Especially while using these acids for educational purposes, they are diluted to a certain limit. You may read our post on 100 examples of acids.

Properties of dilute acids

Diluted acids are sour in taste, but relatively less sour compared to the concentrated form. You can try this by adding water to vinegar and comparing the taste of the original and diluted solution.
Dilute acids can still dissolve in water and conduct electricity. They dissociate in water to yield hydronium ions.
Acids can be corrosive even if they are diluted. It depends on the extent of dilution. So, acids should be always handled with care.
Dilute acids can also change the color of blue litmus paper red
Dilute acids have less concentration of hydrogen ions compared to the concentrated form.
Dilute acids have a higher pH compared to concentrated forms.
They are relatively easy to handle.
They release hydrogen gas when reacted with metals.
They react with a base to form salt and water.

How to dilute acids

Water consists of water molecules that help to reduce the concentration of ions in the solution by adding water to acid. The pH progressively increases towards 7. As a result, the acid becomes less acidic.

Diluting acids can be very hazardous while performing the procedure. Therefore while performing it, safety precautions should be taken like lab coats, gloves, etc. After properly measuring the concentration of acid and water, the acid should be added to the water. water should never be added to acid as a huge amount of energy is generated and can cause corrosive fumes and droplets to splash on you. This heat has to be absorbed so it is better to add acid to water. This heat will go into the concentrated acid. The hydrogen bonding in water needs much higher energy to make it boil. So, it is safe to add acid to water drop by drop.

Handling of dilute acids

Dilution of acids should be done with proper safety precautions. We should use proper PPE’s such as chemical-resistant aprons, Chemical-resistant gloves, and chemical splash goggles while handling them to prevent injuries. Breathing should be avoided as some acids are injurious if inhaled. Preferably, the dilution can be performed in a fume hood.

Storage of dilute acids

Small quantities of dilute acids should be stored after labeling properly with the concentration and pH clearly mentioned. Fuming acids, acid chloride should be stored in ventilated areas. Flammable liquids should be stored separately and should be labeled with a warning sign.

Are weak acids the same as dilute acids?

No. Acids can be classified into weak or strong based on the ability to release H+ ions in a solution. But, dilute and concentrated acids are classified based on the concentration of acid. For example, a strong acid like sulfuric acid can be a dilute acid depending on the concentration. And a weak acid like acetic acid can also be a dilute acid. For example, vinegar is a weak acid that is also a dilute acid.

What is the impact of dilution on the pH of an acid?

In a dilute acid, the concentration of acid is very less. The pH value is based on the concentration of H⁺ ions. Hence, the dilution is directly proportional to the value of pH. A dilute acid will have a higher pH compared to concentrated acid.