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Chapter Analysis
Beginner8 pages • EnglishQuick Summary
The chapter 'Acids, Bases, and Salts' explores the chemical nature of acids and bases and their interaction. It explains familiar substances that contain these chemicals and introduces indicators such as litmus and phenolphthalein used to test acidic and basic properties. The process of neutralization, which occurs when an acid and a base react to form salt and water, is described. The chapter also discusses the practical applications and implications of acids and bases in daily life, including indigestion relief, ant venom treatment, soil treatment in agriculture, and industrial waste management to prevent environmental damage.
Key Topics
- •Acids and their properties
- •Bases and their properties
- •Indicators such as litmus and phenolphthalein
- •Neutralization reaction
- •Applications of neutralization in daily life
- •Safety while handling acids and bases
- •Environmental effects of acids, like acid rain
- •Treatment of acidic soils in agriculture
Learning Objectives
- ✓Understand the concepts of acids and bases, including their properties and examples.
- ✓Learn about different types of indicators used to detect acidic and basic substances.
- ✓Comprehend the process and significance of neutralization reactions.
- ✓Identify the practical applications of acids, bases, and salts in everyday life.
- ✓Recognize the environmental impact of acid rain and ways to counteract it.
- ✓Apply knowledge of acids and bases to explain real-world scenarios involving soil treatment and waste management.
Questions in Chapter
State differences between acids and bases.
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Ammonia is found in many household products, such as window cleaners. It turns red litmus blue. What is its nature?
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Name the source from which litmus solution is obtained. What is the use of this solution?
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Is the distilled water acidic/basic/neutral? How would you verify it?
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Describe the process of neutralisation with the help of an example.
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Mark ‘T’ if the statement is true and ‘F’ if it is false: (i) Nitric acid turn red litmus blue. (T/F) (ii) Sodium hydroxide turns blue litmus red. (T/F) (iii) Sodium hydroxide and hydrochloric acid neutralise each other and form salt and water. (T/F) (iv) Indicator is a substance which shows different colours in acidic and basic solutions. (T/F) (v) Tooth decay is caused by the presence of a base. (T/F)
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Explain why: (a) An antacid tablet is taken when you suffer from acidity. (b) Calamine solution is applied on the skin when an ant bites. (c) Factory waste is neutralised before disposing it into the water bodies.
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Three liquids are given to you. One is hydrochloric acid, another is sodium hydroxide and third is a sugar solution. How will you identify them? You have only turmeric indicator.
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Blue litmus paper is dipped in a solution. It remains blue. What is the nature of the solution? Explain.
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Consider the following statements: (a) Both acids and bases change colour of all indicators. (b) If an indicator gives a colour change with an acid, it does not give a change with a base. (c) If an indicator changes colour with a base, it does not change colour with an acid. (d) Change of colour in an acid and a base depends on the type of the indicator. Which of these statements are correct? (i) All four (ii) a and d (iii) b, c and d (iv) only d
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Additional Practice Questions
What is the role of indicators in identifying acids and bases?
easyAnswer: Indicators are substances that change color when added to acidic or basic solutions. They help identify whether a solution is acidic or basic by showing a color change. Common indicators include litmus, phenolphthalein, and turmeric.
How does neutralization impact the environment, especially concerning industrial waste?
mediumAnswer: Neutralization plays a crucial role in managing industrial waste, as it involves adding basic substances to acidic waste to prevent environmental pollution. This process neutralizes harmful acids, thus protecting water bodies and aquatic life from potential damage.
Why are acids commonly found in foods that taste sour?
easyAnswer: Sour-tasting foods often contain natural acids such as acetic acid in vinegar or citric acid in citrus fruits. The sour taste is due to the presence of hydrogen ions released by acids, which react with taste receptors on the tongue.
Discuss how acid rain forms and its effects on the environment.
hardAnswer: Acid rain forms when pollutants like sulfur dioxide and nitrogen oxides in the atmosphere react with water vapor to form sulfuric and nitric acids. It can damage buildings, harm aquatic life, and impact plant growth negatively by altering soil chemistry.
How can farmers correct soil acidity to improve crop growth?
mediumAnswer: Farmers often add bases like lime (calcium oxide) or slaked lime (calcium hydroxide) to acidic soils to neutralize excessive acidity, thereby creating a more favorable environment for plant growth and improving crop yield.
Explain the chemical reaction that occurs when an antacid is used to treat stomach acidity.
mediumAnswer: Antacids contain bases such as magnesium hydroxide, which neutralize excess stomach hydrochloric acid through a chemical reaction, resulting in the formation of salt and water and the alleviation of acidity-related discomfort.
Why is it dangerous to handle strong acids and bases without proper safety precautions?
mediumAnswer: Strong acids and bases are corrosive and can cause severe skin burns and damage to tissues upon contact. Proper safety precautions, such as using gloves and goggles, are essential to prevent accidents and injuries.
Describe the chemical composition of a typical household cleaning base and its action mechanism.
hardAnswer: A typical household cleaning base, like ammonia, is composed of ammonium hydroxide. It cleans by saponification of fats, cutting through grease and stains by reacting with oils to form soap-like compounds that can be easily rinsed away.
NCERT Exemplar
AvailablePractice with NCERT Exemplar problems and solutions for this chapter. Exemplar problems are designed to help you master the concepts with advanced-level questions.
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