Students can practice the best Class 7 Science MCQ and Exploring Substances Acidic Basic and Neutral Class 7 Science Curiosity Chapter 2 MCQ Online Test with Answers for exam preparation.
Class 7 Science Chapter 2 Exploring Substances Acidic Basic and Neutral MCQ
Exploring Substances Acidic Basic and Neutral MCQ Class 7
MCQ On Exploring Substances Acidic Basic and Neutral Class 7
Question 1.
National Science Day is celebrated on:
(a) 28 February
(b) 06 April
(c) 02 March
(d) None of these
Answer:
(a) 28 February
Question 2.
Litmus is obtained from the:
(a) Mango
(b) Lichens
(c) Tomato
(d) Guava
Answer:
(b) Lichens
Question 3.
Synthetic indicators are made in:
(a) humes
(b) market
(c) labs
(d) none of these
Answer:
(c) labs
Question 4.
Lemon contains:
(a) Acetic acid
(b) Oxalic acid
(c) Ascorbic acid
(d) Citric acid
Answer:
(d) Citric acid
Question 5.
Hydrangea plant grows in:
(a) Plains
(b) Himalayan region
(c) Seas
(d) All of these
Answer:
(b) Himalayan region
Question 6.
Turmeric is a member of the ginger family. It is called:
(a) Golden spice
(a) and (b)
(b) Mint
(c) Both
(d) None of these
Answer:
(a) Golden spice
Question 7.
The red ant bites a person in hand. It injects:
(a) Formic acid
(b) Acetic acid
(c) Lactic acid
(d) Oxalic acid
Answer:
(a) Formic acid
Question 8.
Factory waste is acidic in nature. It kills:
(a) Fishes in a lake
(b) Crows in garden
(c) Both (a) and (b)
(d) None of these
Answer:
(a) Fishes in lake
Question 9.
In too acidic soils, plants:
(a) Show poor health
(b) Do not grow well
(c) May die early
(d) None of these
Answer:
(b) Do not grow well
Question 10.
Complete the following neutralisation reaction:
Acid + _______→ Salt + Water + Heat
The answer is:
(a) Acid
(b) Base
(c) Both (a) and (b)
(d) None of these
Answer:
(c) Both (a) and (b)
Question 11.
An example of a natural indicator is:
(a) litmus
(b) methyl orange
(c) phenolphthalein
(d) All of the above
Answer:
(a) litmus
Question 12.
Baking soda turns:
(a) turmeric to red
(b) purple-cabbage juice to green
(c) red litmus to blue
(d) all of the above
Answer:
(d) all of the above
Question 13.
Substances that are produced when acids react with bases are:
(a) salts
(b) indicators
(c) litmus
(d) antacid
Answer:
(a) salts
Question 14.
Which of the following is not an acid-base indicator?
(a) Litmus
(b) Methyl orange
(c) Phenolphthalein
(d) Sulphur
Answer:
(d) Sulphur
Question 15.
Which of the following is acidic in nature?
(a) Lime juice
(b) Human blood
(c) Lime water
(d) Antacid.
Answer:
(a) Lime juice
Question 16.
An aqueous solution turns red litmus solution blue. Excess addition of which of the following solution would reverse the change?
(a) Baking powder
(b) Lime
(c) Ammonium hydroxide solution
(d) Hydrochloric acid.
Answer:
(d) Hydrochloric acid.
Question 17.
To protect tooth decay, we are advised to brush our teeth regularly. The nature of the tooth paste commonly used is:
(a) acidic
(b) neutral
(c) basic
(d) corrosive
Answer:
(c) basic
Question 18.
Which of the following is not a mineral acid?
(a) Hydrochloric acid
(b) Citric acid
(c) Sulphuric acid
(d) Nitric acid
Answer:
(b) Citric acid
Question 19.
Colours of phenolphthalein indicator in acidic and basic medium, respectively, are:
(a) pink and colourless
(b) colourless and pink
(c) blue and red
(d) red and blue
Answer:
(b) colourless and pink
Question 20.
Litmus, a natural dye, is an extract of which of the following?
(a) Red hibiscus
(b) Lichen
(c) Beetroot
(d) Purple cabbage
Answer:
(a) Red hibiscus
Exploring Substances Acidic Basic and Neutral Class 7 Assertion Reason Questions
Given below are two statements, one labelled as Assertion (A) and the other labelled as Reason (R).
(a) Both (A) and (R) are true and (R) is correct explanation of (A).
(b) Both (A) and (R) are true and (R) is not correct explanation of (A).
(c) (A) is true but (R) is false.
(d) (A) is false but (R) is true.
1. Assertion (A): Acids taste sour but bases are bitter and soapy to touch.
Reason (R): The acids change blue litmus to red. The bases turn red litmus to blue.
Answer:
(b) Both (A) and (R) are true and (R) is not correct explanation of (A).
2. Assertion (A): Solution of substances which show different colours in acidic, basic and neutral solutions are known as indicators.
Reason (R): The litmus acts as natural indicator having purple colour in neutral medium. But in acidic medium, this shows red colour and the blue colour in basic medium.
Answer:
(a) Both (A) and (R) are true and (R) is correct explanation of (A).
3. Assertion: The reaction between an acid and a base is known as neutrilisation reaction.
Reason: The neutrilisation reaction forms salt and water as a product.
Answer:
(a) Both (A) and (R) are true and (R) is correct explanation of (A).
4. Assertion: Acid turns blue litmus red and bases turn red litmus blue.
Reason: Substance which neither acid nor basic is called neutral.
Answer:
(b) Both (A) and (R) are true and (R) is not correct explanation of (A).
Exploring Substances Acidic Basic and Neutral Class 7 Fill in the Blanks
1. The substances around us are acidic, basic, _______ in nature.
Answer:
neutral
2. An acid changes colour of blue litmus to _______.
Answer:
red
3. Tamarind contains _______ acid.
Answer:
tartaric
4. The substances which taste sour are _______.
Answer: acids
5. Red rose is use as an _______.
Answer:
indicator
6. Yellow colour of turmeric changes red in _______ solutions.
Answer:
basic
7. Acid + base forms salt and water with evolution of heat. This reaction is called _______.
Answer:
neutralisation
8. Lichens are mutual association of an algae and a _______.
Answer: fungus
9. The curd contains _______ acid.
Answer:
lactic
10. Litmus is available in solution and paper _______.
Answer:
strips
Exploring Substances Acidic Basic and Neutral Class 7 True or False
1. The acids have sour taste.
Answer: True
2. Orange and lemon are citrus fruits.
Answer: True
3. Curd contains acetic acid.
Answer: False
4. China rose is a nature indicator.
Answer: True
5. The reaction of an acid and a base is neutralisation.
Answer: True
6. If soil is too acidic, quicklime is added to it.
Answer: True
7. Tartaric acid occurs in the grapes.
Answer: True
8. Turmeric can distinguish between acidic and neutral substances.
Answer: False
9. The plants grow well in neutral soils.
Answer: True
10. Red rose extract is an example of acid base indicator.
Answer: True