The key difference between weak acid and dilute acid is that weak acid is a compound that partially dissociates when dissolved in water, whereas dilute acid is a solution containing more water than acid.
An acid is a compound that can dissociate in water to release protons (hydrogen ions). Therefore, acids have a pH lower than 7. There are two types of acids as strong acids and weak acids according to acid strength. But according to the concentration of the acid, there are two types of acid solutions as concentrated acid and dilute acid.
CONTENTS
1. Overview and Key Difference
2. What is Weak Acid
3. What is Dilute Acid
4. Side by Side Comparison – Weak Acid vs Dilute Acid in Tabular Form
5. Summary
What is a Weak Acid?
A weak acid is a compound that partially dissociates into its ions when dissolved in water. Weak aid is the conjugate acid of a weak base. Moreover, a weak acid has a high pH value compared to a strong aid of the same concentration. When writing the chemical equation for the dissociation of a weak acid, we use a double arrow to include both forward and backward reactions because the dissociation of a weak acid is reversible.
Figure 01: Speciation of a Weak Acid (AH is the Weak Acid)
A weak acid becomes weak because of the less polar nature of the acid compound; if the compound is more polar, the protons can easily leave the acid molecule, but here, since the compound is less polar, it is difficult to break down the chemical bonds. Some examples of weak acids include acetic acid, formic acid, HF acid, hydrogen sulfide, etc.
What is a Dilute Acid?
Dilute acid is an aqueous solution having a low concentration of acid. That means; the dilute acid solution has more water compared to the acid content. The dilute acid can be either a weak acid or a strong acid. The term “dilute” only describes the concentration of the acid. The opposite of dilute acid is concentrated acid.
Figure 02: Concentrated HCl Acid
Furthermore, we can dilute an acid by adding more water. However, adding water to a concentrated acid is hazardous. Therefore, the safe method is to add acid to water. Diluting acids is very important because using highly concentrated acids can cause severe burns if it touches the skin.
What is the Difference Between Weak Acid and Dilute Acid?
Weak acid comes under the classification of acids according to acid strength, while dilute acid comes under the category of concentration of acids. The key difference between weak acid and dilute acid is that the weak acid is a compound that partially dissociates when dissolved in water, whereas the dilute acid is a solution containing more water than acid. However, the dilution of acid does not affect the reactivity of the acid. That means, a strong acid does not become a weak acid upon dilution. But, weak acids are less reactive by nature.
Below infographic summarizes the difference between weak acid and dilute acid.
Summary – Weak Acid vs Dilute Acid
Weak acid comes under the classification of acids according to acid strength, and the dilute acid comes under the category of concentration of acids. The key difference between weak acid and dilute acid is that weak acid is a compound that partially dissociates when dissolved in water, whereas dilute acid is a solution containing more water than acid.
Reference:
1. Helmenstine, Anne Marie. “Weak Acid Definition and Examples in Chemistry.” ThoughtCo, May. 5, 2019, Commons Wikimedia.
Image Courtesy:
1. “Weak acid speciation” By P. Gans, own drawing, uploader was Petergans at en.wikipedia – Transferred from en.wikipedia to Commons by LeaW (Public Domain) via Commons Wikimedia
2. “Hydrochloric acid 05” (Public Domain) via Commons Wikimedia