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Dilute Acids

Apr 29, 2023, 16:45 IST

Acids are fundamental substances essential in our world, playing a crucial role in our daily lives, ranging from foods to the products we use. Adding a small amount of concentrated acid to water creates a weak dilute acid solution. This write-up will delve into the basics of dilute acids.

Introduction

Acids are chemical compounds that can release hydrogen ions (H + ) into the water, ultimately affecting the solution's pH level or acidity. Acids generally have a pH below 7. Adding a small quantity of concentrated acid to water produces a feeble solution called dilute acids. These solutions contain low acid levels, and their attributes vary based on the acid used. Dilute acids usually have a lower pH than pure water, and the level of acidity differs based on the acid concentration in the solution.

What is Dilute Acid?

Dilute acids refer to solutions that have a relatively low concentration of acid. These solutions are typically created by mixing a small amount of concentrated acid with water, which results in a weaker solution.

For example, adding a small quantity of concentrated sulfuric acid to water produces a dilute sulfuric acid solution. The resulting solution has a lower pH than pure water, and its properties are determined by the specific acid used. Other examples of dilute acids include dilute hydrochloric acid and dilute acetic acid.

Properties of Dilute Acids

The properties of dilute acids are similar to concentrated acids, but there are a few distinct properties.

  • Dilute acids have a sour taste, a characteristic property of acidic substances.
  • Dilute acids have a lower pH than pure water, indicating their acidic nature.
  • Dilute acids can corrode certain materials, including metals and some plastics, due to their acidic nature.
  • Dilute acids can conduct electricity due to the presence of free hydrogen ions.
  • Dilute acids are generally colorless liquids. However, some acids, such as chromic acid, can have distinct colors like yellow or red.
  • Dilute acids can react with bases to form salts and water like strong acids.

Chemical Reactivity of Dilute Acids

Dilute acids exhibit chemical reactivity, leading to the formation of various products, much like concentrated acids.

Reaction with Metals

Dilute acids can react with specific metals, including magnesium and zinc, to create a metal salt and hydrogen gas. For instance, when a diluted hydrochloric acid solution is combined with zinc, the reaction yields hydrogen gas and zinc chloride, as shown in the chemical equation below:

Zn + 2HCl → ZnCl 2 + H

Reaction with Base

When dilute acids react with bases, they create salt and water. For instance, the reaction of dilute hydrochloric acid with sodium hydroxide yields sodium chloride and water, represented by the equation:

HCl + NaOH → NaCl + H 2 O

Reaction with Alkene

Dilute acids can react with an alkene to form alcohol. For example, when dilute sulfuric acid is added to ethene, it produces ethyl alcohol, as shown in the following reaction:

CH 2 =CH 2 + H 2 SO 4 → CH 3 -CH 2 -OH

Reaction with Carbonates

Dilute acids react with carbonates to produce carbon dioxide gas, salt, and water. For example, when dilute hydrochloric acid is added to calcium carbonate, it produces calcium chloride, water, and carbon dioxide gas, as shown in the following reaction:

CaCO 3 + 2HCl → CaCl 2 + CO 2 + H 2 O

Reaction with metal oxides and hydroxides

Dilute acids react with metal oxides or hydroxides to produce salt and water. For example, when dilute sulfuric acid is added to copper(II) oxide, it produces copper(II) sulfate and water. Similarly, when dilute sulfuric acid is added to magnesium hydroxide, it produces magnesium sulfate and water as shown in the following reaction:

CuO + H 2 SO 4 → CuSO 4 + H 2 O

Mg(OH) 2 + H 2 SO 4 → MgSO 4 + 2H 2 O

Applications

  • Dilute acids, such as sulfuric acid and hydrochloric acid, are used to remove rust, mineral deposits, and other impurities from surfaces.
  • Dilute acids are used in the food industry for various purposes, such as preserving food, making pickles, and controlling the pH levels in certain foods.
  • Dilute acids are used to produce fertilizers, such as ammonium nitrate and superphosphate.
  • Dilute acids are used in the petroleum industry to refine crude oil.

Frequently Asked Questions (FAQs)

Q1. What are dilute acids?

Ans. Dilute acids are solutions with a relatively low concentration of acid, created by mixing a small amount of concentrated acid with water to produce a weaker solution. Examples of dilute acids include dilute hydrochloric acid, dilute sulfuric acid, and dilute acetic acid.

Q2. What are the properties of dilute acids?

Ans. Dilute acids have a sour taste, a lower pH than pure water, and the ability to corrode certain materials, such as metals and some plastics, due to their acidic nature. They can conduct electricity and react with bases to form salts and water, similar to strong acids.

Q3. What chemical reactions can dilute acids undergo?

Ans. Dilute acids can react with metals, bases, alkene, carbonates, and metal oxides or hydroxides to form various products, such as hydrogen gas, salts, water, and carbon dioxide gas. Examples of reactions include the reaction of dilute hydrochloric acid with calcium carbonate and the reaction of dilute sulfuric acid with copper(II) oxide.

Q4. What are the applications of dilute acids?

Ans. Dilute acids have several applications in various industries. They are used to remove impurities from surfaces, preserve food, control pH levels in certain foods, produce fertilizers, and refine crude oil in the petroleum industry.

Q5. How are dilute acids different from concentrated acids?

Ans. Dilute acids have a lower concentration of acid compared to concentrated acids. Dilute acids have a weaker solution and lower pH than pure water, while concentrated acids have a more potent solution and a pH of less than 7. Dilute acids can still exhibit chemical reactivity and corrosiveness, but to a lesser extent than concentrated acids.

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