CBSE Class 7 Science Exploring Substances: Acidic Basic and Neutral (Class 7 NCERT New) Quiz 3

1. Which plant is litmus extracted from?

A Ferns B Lichens C Moss D Algae

2. What color does red rose extract turn in a basic solution?

A Red B Green C Yellow D Blue

3. Which of the following is NOT an acid?

A Baking soda B Tamarind C Lemon D Vinegar

4. What is the effect of neutral substances on litmus?

A Turns it green B No effect C Turns it blue D Turns it red

5. Which of the following is a property of alkalis?

A Taste bitter B Insoluble in water C Have pH values of less than 7 D Change blue litmus paper to red

6. Solution X has a pH value of . What colours are observed when universal solution and methyl orange are added to solution X separately?

A Universal: Yellow; Methyl orange: Blue B Universal: Blue; Methyl orange: Yellow C Universal: Pink; Methyl orange: Yellow D Universal: Blue; Methyl orange: Pink

7. Malic acid powder cannot change the colour of blue litmus paper. What substance must be added to malic acid powder so that the colour of blue litmus paper can change?

A Magnesium ribbon B Chloroform C Distilled water D Liquid benzene

8. Which of the following substances has the highest pH value?

A Hydrochloric acid B Fresh milk C Salt solution D Soap solution

9. An acidic solution undergoes neutralisation when it reacts with substance Z. What is substance Z?

A Phenolphthalein B Alkali C Salt solution D Distilled water

10. The following equation shows a neutralisation reaction: Acid + Alkali → X + Y. Which of the following is X and Y?

A X: Salt; Y: Water B X: Salt; Y: Hydrogen C X: Water; Y: Hydrogen D X: Water; Y: Carbon dioxide