Class 10 Chemistry Chapter 3
Study of Acid , Bases and Salts
Important Questions

Here, you'll discover significant inquiries pertaining to Chapter 3 : Acid , Bases and Salts for ICSE Class 10 Chemistry. These inquiries are carefully designed to aid students in preparing for the ICSE Class 10 Chemistry Examination in 2023–24. Engaging with different question formats allows students to address uncertainties, improve their exam preparedness, boost their self-assurance, and polish their ability to solve problems.

Introduction

In ICSE Class 10 Chemistry Chapter 3, Acid, Bases, and Salts, you will explore the following topics: 

• An introduction to Acids, Bases, and Salts. 
• Understanding Ion Concentration in Mineral Acids, Alkalis, and Salts. 
• Examination of Litmus and pH paper. Exploring Salts and Different Types of Salts.
• Studying the Effects of Dilute Acids on Salts. Learning about the Preparation of Normal Salts.

For more information on acid bases and salts class 10 important questions ICSE, and acid bases and salts class 10 ICSE important questions, you can refer to Oswal textbooks or oswal.io.

What is the Study of Acid , Bases and Salts?

In ICSE Class 10 Chemistry Chapter 3 we study about following Concepts:-
‍
Acids
The property that defines acids is their acidity, and typically, acidic substances have a distinctly sour taste. Besides hydrochloric acid, there exists a wide variety of other acid types in our surroundings. For example, citric and ascorbic acids are found in citrus fruits like lemons and oranges, while tartaric acid can be found in tamarind paste.Interestingly, the terms 'acid' and 'acidity' are derived from the Latin word 'acidus,' which means sour. When a blue litmus paper is dipped into an acid, it will undergo a colour change and turn red, while a red litmus paper will remain unaffected. Additionally, when acids react with certain metals, they release hydrogen gas.

Bases
‍Bases have the characteristic of turning red litmus paper into blue, with blue litmus paper remaining blue when exposed to them. These substances typically have a bitter taste and impart a soapy sensation. Other common examples of bases include sodium bicarbonate, which is utilised in cooking, and household bleach.

Salts
In addition to sodium chloride, other commonly encountered salts include sodium nitrate, barium sulphate, and others. Sodium chloride, or common salt, results from the reaction between hydrochloric acid (an acid) and sodium hydroxide (a base). Solid sodium chloride consists of a cluster of positively charged sodium ions and negatively charged chloride ions that are held together by electrostatic forces.The strength of electrostatic forces between oppositely charged ions depends on the dielectric constant of the medium. In simpler terms, when a substance with acidic properties and a substance with basic properties are combined, they may produce salts.Water, often referred to as the universal solvent, possesses a dielectric constant of 80. Consequently, when sodium chloride dissolves in water, the water's dielectric constant diminishes the electrostatic force, allowing the ions to move freely within the solution. Furthermore, these ions are separated from each other due to their interaction with water molecules through a process known as hydration.

Class 10 Chemistry Chapter 3 Study of Acids , Bases and Salts Important Questions and Answers

Q1. What happens when a solution of an acid is mixed with a solution of a base in a test tube?

Options

(a) Temperature of the solution decreases.
(b) Temperature of the solution increases.
(c) Temperature of the solution remains the same.
(d) None of the above

Ans. (b) Temperature of the solution increases.

Explanation:
When acid is added to any base, the temperature of the acid-base reaction rises. This is because this process is exothermic in nature, which means a large amount of heat is evolved, known as heat of neutralisation, causing a temperature to increase.

Q2. Sodium carbonate is a basic salt because it is a salt of a:

Options

(a) Strong acid and strong base
(b) Weak acid and weak base
(c) Strong acid and weak base
(d) Weak acid and strong base

Ans. (d) Weak acid and strong base
Explanation:
Sodium carbonate is a basic salt because it is derived from a weak acid (carbonic acid) and strong base (sodium hydroxide).

Q3. State what would you observe when:
(a) Washing soda crystals are exposed to the atmosphere.
(b) The salt ferric chloride is exposed to the atmosphere.

Explanation:
(a) When crystals of washing soda are exposed to air, they lose 9 water molecules of crystallisation and become monohydrate forming a white powder. Thus, shows the phenomenon of efflorescence.
\(Na_2CO_3.10H_2O\underrightarrow{Dry\space air}Na_2CO_3.H_2O+9H_2O\)
(b) The salt ferric chloride, when exposed to the atmosphere, absorbs water molecules to become moist and shows the phenomenon of deliquescence.

Q4. Name three classes of substances, which react with an acid to form salts. Write equations to describe their reactions with suitable acids.

Explanation:
Metals, bases, and metallic carbonates are three distinct types of chemicals that interact with acids to generate salts.
(I) With the formation of zinc sulphate and the release of hydrogen gas, zinc, a metal, reacts with dilute sulfuric acid.
Zn + H₂SO₄ →  ZnSO₄ + H₂
(ii) To create sodium nitrate and water, the base sodium hydroxide combines with diluted nitric acid.
HNO₃ + NaOH → HNO₃ + NaNO₃ + H₂O
(iii) When magnesium carbonate, a metallic carbonate, interacts with diluted hydrochloric acid, magnesium chloride water and carbon dioxide gas is released.

Q5. Give equations and indicate briefly the procedure, you would adopt to prepare :
(i) Crystals of ferrous sulphate from iron filings.
(ii) Crystals of zinc sulphate from zinc carbonate.
(iii) Copper (II) carbonate from copper (II) sulphate.

Explanation:
(i) 50 cm³ of diluted sulfuric acid should be placed in a beaker, and it should be heated on a wire gauge. Once the hydrogen effervescence has stopped, add the iron fillings while stirring continuously. Filter the solution to remove any extra iron fillings, and then evaporate the mixture until a saturated solution is created. Separate ferrous sulphate crystals are formed after cooling the solution.
Fe + H₂SO₄ → FeSO₄ + H₂ .
(ii) Take 5 g of zinc carbonate, add diluted sulfuric acid, and heat until all the zinc carbonate is dissolved and the carbon dioxide bubbles have stopped. The solution should be heated and filtered in an evaporating dish until a saturated solution forms. To get the zinc sulphate crystals, let the solution cool.
ZnCO₃ + H₂SO₄ → ZnSO₄ + H₂O + CO_2 
‍ZnSO₄ + 7H₂O → ZnSO₄ .7H₂O (Hydrated zinc (II) sulphate)
(iii) Take 5 g of copper (II) sulphate and mix it with water in a beaker. Add sodium carbonate in a strong solution now to this mixture. Copper (II) carbonate precipitates out in a pale blue colour. When you filter a solution, sodium sulphate dissolves in the filtrate and leaves a blue copper carbonate precipitate as a residue on the filter paper.
CuSO₄ + Na₂CO₃ → CuCO₃ + Na₂SO₄ (Light blue colour)

ICSE Class 10 Chemistry Chapter wise Important Questions

Conclusion

The study of "Acids, Bases, and Salts" in ICSE Class 10 Chemistry has illuminated the fundamental principles governing the behaviour of these essential chemical entities. This chapter has provided us with a profound understanding of the unique characteristics, properties, and reactions of acids, bases, and salts.Understanding the vital role of salts in various chemical processes and their importance in daily life has enriched our knowledge. For those seeking to excel in this critical aspect of chemistry, additional practice and resources can be instrumental. Oswal.io offers a comprehensive collection of questions and study materials tailored to enhance your learning experience. These resources not only enable you to test your understanding but also provide opportunities to refine your skills and reinforce the principles covered in this chapter.

Frequently Asked Questions

Q1 : What constitutes a salt within the realm of acids, bases, and salts?

Ans: In the field of chemistry, a salt is a product formed through the chemical reaction between an acid and a base. Salts consist of positively charged ions (cations), originating from bases, and negatively charged ions (anions), originating from acids. The process of combining an acid and a base to create a salt is referred to as a neutralisation reaction.

Q2: Can NH₄Cl be classified as an alkaline salt?

Ans: Ammonium chloride, with the chemical formula NH₄Cl, is considered an acidic salt. This classification arises from the fact that it is formed by the combination of a strong acid, hydrochloric acid, and a weak base, ammonium hydroxide.

Q3 : What are the two categories of acids?

Ans: There are two primary categories of acids: organic acids and inorganic acids. Inorganic acids are also known as mineral acids. Generally, organic acids are not as potent as inorganic acids when considered as a group. The key distinction between these two categories lies in the presence of carbon within the compound; inorganic acids lack carbon.
Inorganic acids – Inorganic acids are frequently referred to as mineral acids. In their anhydrous form, they can exist as either gases or solids. An inorganic anhydride is an oxide of a metalloid that can combine with water to form an inorganic acid. Examples include:

• Sulphuric acid (H₂SO₄)
• Phosphoric acid (H₃PO₄)
• Nitric acid (HNO₃)

Organic acids – Organic acids are known for their corrosive and toxic properties.
Corrosiveness refers to the potential harm these acids can inflict on tissues they come into contact with. Organic acids and their derivatives encompass a wide range of substances and are employed in various chemical manufacturing processes. The diversity in chemical structure among organic acids is a notable characteristic. Examples include:

• Acetic acid
• Citric acid
• Formic acid

Q4 : Is salt considered alkaline or acidic?

Ans:  A salt is alkaline solely when it incorporates the conjugate base of a weak acid. For instance, sodium chloride includes chloride ions (Cl^-), which are the conjugate base of hydrochloric acid (HCl).

Q5 : What occurs during the reaction between salt and HCl?

Ans: When an acid interacts with a metal, the outcome is the formation of a salt along with the release of hydrogen gas
acid + metal → salt + hydrogen
The specific salt generated in this reaction depends on the particular acid and metal involved.For example, when sodium metal reacts with hydrochloric acid, it results in the production of hydrogen gas and sodium chloride
2Na(s) + 2HCl(aq) → 2NaCl(aq) + H₂(g)