With reference to soil treatment, consider the following statements: 1. Plants grow best when the soil is highly acidic. 2. If the soil is too acidic, it is treated with bases like quick lime or slaked lime. 3. If the soil is basic, organic matter is added to release acids. Which of the statements given above is/are correct?

The correct option is (c). Explanation Soil pH is a critical factor for plant growth, influencing nutrient availability and microbial activity. Most plants thrive in a neutral pH range. When soil becomes too acidic or too basic due to environmental factors or chemical fertilizers, neutralization techniques are employed to restore balance. Statement-wise Analysis: - Statement 1 is Incorrect: Plants generally do not grow well when the soil is either highly acidic or highly basic. Most crops require a neutral or slightly acidic to slightly alkaline soil pH (typically between 6.0 and 7.5) for optimal growth and nutrient absorption. - Statement 2 is Correct: When soil is too acidic, it contains an excess of hydrogen ions. To neutralize this acidity, bases are added. Common treatments include quick lime (calcium oxide) or slaked lime (calcium hydroxide). These substances react with the soil acids to raise the pH towards a neutral level. - Statement 3 is Correct: When soil is too basic (alkaline), it requires acidification to lower the pH. Organic matter (such as compost or manure) is added to the soil. As this organic matter decomposes, it releases acids which neutralize the excess bases present in the soil. Key Takeaway: Soil treatment relies on neutralization: bases (like lime) are used to treat acidic soils, while organic matter (which releases acids) is used to treat basic soils.

NCERT Class 7 Science — Chapter 1: Acids, bases and salts

mcqmedium

With reference to soil treatment, consider the following statements:

Plants grow best when the soil is highly acidic.
If the soil is too acidic, it is treated with bases like quick lime or slaked lime.
If the soil is basic, organic matter is added to release acids.

Which of the statements given above is/are correct?

Official previous-year question

Verified 1 Aug 2026.

Options

A1 and 2 only
B2 only
C2 and 3 only
D1, 2 and 3

Did you get this right?

Solution

The correct option is (c).

Explanation

Soil pH is a critical factor for plant growth, influencing nutrient availability and microbial activity. Most plants thrive in a neutral pH range. When soil becomes too acidic or too basic due to environmental factors or chemical fertilizers, neutralization techniques are employed to restore balance.

Statement-wise Analysis:

Statement 1 is Incorrect: Plants generally do not grow well when the soil is either highly acidic or highly basic. Most crops require a neutral or slightly acidic to slightly alkaline soil pH (typically between 6.0 and 7.5) for optimal growth and nutrient absorption.
Statement 2 is Correct: When soil is too acidic, it contains an excess of hydrogen ions. To neutralize this acidity, bases are added. Common treatments include quick lime (calcium oxide) or slaked lime (calcium hydroxide). These substances react with the soil acids to raise the pH towards a neutral level.
Statement 3 is Correct: When soil is too basic (alkaline), it requires acidification to lower the pH. Organic matter (such as compost or manure) is added to the soil. As this organic matter decomposes, it releases acids which neutralize the excess bases present in the soil.

Key Takeaway:

Soil treatment relies on neutralization: bases (like lime) are used to treat acidic soils, while organic matter (which releases acids) is used to treat basic soils.

Your note

More from Chapter 1: Acids, bases and salts

With reference to the chemical nature of substances, consider the following statements: 1. All substances that taste sour contain acids. 2. Substances that taste bitter and feel soapy on touching are generally acidic in nature. 3. Baking soda is an example of a substance that has a bitter taste and is basic in chemical nature. Which of the statements given above is/are correct?

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Consider the following statements regarding naturally occurring acids: 1. Lactic acid is the primary constituent of vinegar. 2. Oxalic acid is found in spinach. 3. Ascorbic acid is also known as Vitamin C. Which of the statements given above is/are correct?

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Which one of the following pairs is correctly matched regarding the acid present in the substance?

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With reference to bases and their sources, consider the following pairs: 1. Calcium hydroxide : Lime water 2. Ammonium hydroxide : Window cleaner 3. Magnesium hydroxide : Soap 4. Sodium hydroxide : Milk of magnesia How many of the above pairs are correctly matched?

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Consider the following statements about 'Litmus', a natural indicator: 1. It is extracted from lichens. 2. It has a green colour in distilled water. 3. It turns blue when added to an acidic solution. Which of the statements given above is/are correct?

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The correct option is (c).

Explanation

Statement-wise Analysis:

Statement 1 is Incorrect: Plants generally do not grow well when the soil is either highly acidic or highly basic. Most crops require a neutral or slightly acidic to slightly alkaline soil pH (typically between 6.0 and 7.5) for optimal growth and nutrient absorption.
Statement 2 is Correct: When soil is too acidic, it contains an excess of hydrogen ions. To neutralize this acidity, bases are added. Common treatments include quick lime (calcium oxide) or slaked lime (calcium hydroxide). These substances react with the soil acids to raise the pH towards a neutral level.
Statement 3 is Correct: When soil is too basic (alkaline), it requires acidification to lower the pH. Organic matter (such as compost or manure) is added to the soil. As this organic matter decomposes, it releases acids which neutralize the excess bases present in the soil.

Key Takeaway:

Soil treatment relies on neutralization: bases (like lime) are used to treat acidic soils, while organic matter (which releases acids) is used to treat basic soils.