Last updated on December 9th, 2023 at 09:07 pm
Class 7 Science Acid Base and Salts MCQ
Que: Which substances are considered acidic?
a) Lemon juice, orange juice, curd, and vinegar
b) Baking soda
c) Sugar and salt
d) Milk and water
Answer: a) Lemon juice, orange juice, curd, and vinegar
Que: What taste and texture are associated with baking soda?
a) Sweet and grainy
b) Sour and gritty
c) Bitter and soapy
d) Salty and smooth
Answer: c) Bitter and soapy
Que: What are indicators used for?
a) Determining the color of substances
b) Identifying the taste of substances
c) Testing the pH of substances
d) Changing the texture of substances
Answer: c) Testing the pH of substances
Que: Which of the following is an example of an indicator?
a) Sugar
b) Turmeric
c) Salt
d) Milk
Answer: b) Turmeric
Que: What is litmus commonly used as?
a) A natural dye
b) A cleaning agent
c) A food additive
d) A preservative
Answer: a) A natural dye
Que: What color does litmus turn in distilled water?
a) Red
b) Blue
c) Mauve (purple)
d) Green
Answer: c) Mauve (purple)
Que: What color does litmus turn when added to an acidic solution?
a) Red
b) Blue
c) Green
d) Yellow
Answer: a) Red
Que: What color does litmus turn when added to a basic solution?
a) Red
b) Blue
c) Green
d) Yellow
Answer: b) Blue
Que: How is litmus commonly available for use?
a) As a powder
b) As a liquid
c) As litmus strips or paper
d) As a gel
Answer: c) As litmus strips or paper
Que: What color is litmus paper used to test for acidity?
a) Red
b) Blue
c) Green
d) Yellow
Answer: a) Red
Que: What color is litmus paper used to test for alkalinity?
a) Red
b) Blue
c) Green
d) Yellow
Answer: b) Blue
Que: What happens to litmus paper when it is exposed to a neutral solution?
a) It turns red
b) It turns blue
c) It turns green
d) It remains unchanged
Answer: d) It remains unchanged
Que: What can be used to make turmeric paper?
a) Vinegar
b) Turmeric powder
c) Lemon juice
d) Baking soda
Answer: b) Turmeric powder
Que: How is turmeric paper created?
a) By applying turmeric paste to filter paper and drying it
b) By applying vinegar to blotting paper and drying it
c) By applying lemon juice to filter paper and drying it
d) By applying baking soda to blotting paper and drying it
Answer: a) By applying turmeric paste to filter paper and drying it
Que: What happens to the color of turmeric paper when a drop of soap solution is added?
a) It turns red
b) It turns blue
c) It turns yellow
d) It remains unchanged
Answer: b) It turns blue
Que: What is requested from the teacher for further demonstrations?
a) Turmeric powder
b) Soap solution
c) Dilute solutions of various chemicals
d) Blotting paper
Answer: c) Dilute solutions of various chemicals
Que: What is introduced as a new indicator for the demonstration?
a) Turmeric powder
b) Soap solution
c) Phenolphthalein
d) Blotting paper
Answer: c) Phenolphthalein
Que: What is the initial color of the dilute hydrochloric acid in the test tube?
a) Red
b) Blue
c) Yellow
d) Clear/colorless
Answer: d) Clear/colorless
Que: What is added to the acid in the test tube to observe any change in color?
a) Vinegar
b) Turmeric powder
c) Phenolphthalein solution
d) Soap solution
Answer: c) Phenolphthalein solution
Que: What is the result when an acidic solution is mixed with a basic solution in suitable amounts?
a) The solution becomes acidic
b) The solution becomes basic
c) The solution becomes neutral
d) The solution becomes concentrated
Answer: c) The solution becomes neutral
Que: What happens to the temperature of the reaction mixture during neutralization reactions?
a) It decreases
b) It remains unchanged
c) It increases
d) It fluctuates
Answer: c) It increases
Que: What substance is formed during neutralization reactions?
a) Acid
b) Base
c) Salt
d) Water
Answer: c) Salt
Que: What is the general equation for neutralization reactions?
a) Acid + Base → Salt + Water (without heat evolution)
b) Acid + Base → Salt + Water (with heat evolution)
c) Acid + Base → Salt + Oxygen (with heat evolution)
d) Acid + Base → Salt + Carbon dioxide (with heat evolution)
Answer: b) Acid + Base → Salt + Water (with heat evolution)
Que: Which reaction is given as an example of neutralization?
a) HCl + NaOH → NaCl + H2O
b) H2O + NaCl → HCl + NaOH
c) NaOH + NaCl → HCl + H2O
d) NaCl + H2O → HCl + NaOH
Answer: a) HCl + NaOH → NaCl + H2O
Que: What would be the result of adding dilute sulfuric acid to lime water?
a) The reaction mixture becomes acidic
b) The reaction mixture becomes basic
c) The reaction mixture becomes neutral
d) The reaction mixture becomes hot
Answer: d) The reaction mixture becomes hot
Chapter – Class 7 Science Acids, Bases, and Salts
