Question 21 markMCQSection A

Juice of tamarind turns blue litmus to red. It is because of the presence of an acid called :

Acids, Bases and Salts
Natural Indicators and Acids

Options

(A)methanoic acid
(B)acetic acid
(C)tartaric acid
(D)oxalic acid

Official answer

The correct option is C.

Answer keywords:tartaric acidtamarindblue litmus to red

Marking scheme

  1. 1.1 mark for selecting the correct option (C).

Hint

Recall the natural sources of organic acids. Tamarind is sour due to the presence of tartaric acid.

Quick oral answer

Tamarind contains tartaric acid, which turns blue litmus paper red because it releases hydrogen ions (H+H^+) in aqueous solution.

Common mistakes

  1. 1.Students often confuse the acids present in different natural sources, such as confusing oxalic acid (found in tomatoes) or methanoic acid (found in ant stings) with tartaric acid.

Analysis and explanation

Tamarind contains tartaric acid, which is a naturally occurring organic acid. When tamarind juice is tested with blue litmus paper, the presence of hydrogen ions (H+H^+) from the acid causes the blue litmus paper to turn red, indicating its acidic nature.


  • Option A (methanoic acid) is incorrect because methanoic acid (formic acid) is found in ant stings and nettle stings.
  • Option B (acetic acid) is incorrect because acetic acid is the primary constituent of vinegar.
  • Option C (tartaric acid) is correct because tartaric acid is the characteristic acid present in tamarind.
  • Option D (oxalic acid) is incorrect because oxalic acid is found in tomatoes.

Interesting facts

Tartaric acid is also used as an ingredient in baking powder, where it reacts with sodium hydrogencarbonate to release carbon dioxide gas, making cakes fluffy.

Question details

Q2 of 39 questions

Board
CBSE
Class
Class 10
Subject
Science
Year
2024
Section
Section A
Marks
1
Type
MCQ
Chapter
Acids, Bases and Salts
Topic
Natural Indicators and Acids
Bloom's level
Remembering
Syllabus topic
Acids, bases and salts: Their definitions in terms of furnishing of H+H^+ and OH−OH^- ions, General properties, examples and uses

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Frequently asked questions

How many marks does this question carry in CBSE Class 10 Science 2024?

This question carries 1 mark in the CBSE Class 10 Science 2024 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Acids, Bases and Salts" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Natural Indicators and Acids" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2024 paper?

This is a MCQ question from Section A in the CBSE Class 10 Science 2024 paper.