Ncert- science – class 7- Chapter 4 – Acids, Bases and Salts 1 Welcome to your Ncert- science - class 7- Chapter 4 – Acids, Bases and Salts 1 1. From which plant is litmus paper or litmus solution obtained? Moss Rose Lichen Hibiscus None 2. China rose is which type of indicator? None of the above Natural indicator Olfactory indicator Synthetic indicator None 3. Which of the following is not a property of acid? Acid turns blue litmus to red. Acids are sour in taste Acids change the colour of turmeric None of these None 4. A student puts a drop of the reaction mixture of a saponification reaction first on a blue litmus paper and then on a red litmus paper. He may observe that: there is no change in the blue litmus paper and the red litmus paper turns white there is no change in the red litmus paper and the blue litmus paper turns red no change in colour is observed in both the litmus papers there is no change in the blue litmus paper and the red litmus paper turns blue None 5. What do we observe on pouring acetic acid on red and blue litmus paper? Red litmus becomes colourless and blue litmus remains blue Red litmus remains red and blue litmus turns red. Red litmus turns blue and blue litmus remains blue. Red litmus turns blue and blue litmus turns red. None 6. When honeybee bites, which chemical enters in to our body? Melittin Calcium formate Magnesium hydroxide Formic acid None 7. The colour of pH paper strip at the pH valued of 1,7 and 14 will be : Blue, green and red Green, blue and red Green, red and blue Red, green and blue None 8. Turmeric is a natural indicator. On adding its paste to acid and base separately, which colour would be observed ? Pink in acid and yellow in base Yellow in both acid and base Red in acid and blue in base Yellow in acid and red in base None 9. A solution changes the colour of turmeric paper from yellow to red. The solution is: basic acidic neutral either neutral or acidic None 10. Honey bee stings and ant bites can be _________ using alkaline medicine such as baking powder. Neutralize Prevented None of the above Acidifies None 11. Which indicator is correctly paired up with its proper color if it were added to a base? i. Litmus - blue ii. Phenolphthalein - pinkiii. Methyl orange - yellow (i), (ii) and (iii) (i) and (iii) only (iii) only (i) only None 12. Which one of the following will turn blue-litmus red? Lime water Vinegar Washing soda solution Baking soda solution None 13. Why bee strings are treated by alkaline solutions? Because it is basic in nature None of these. Because it is acidic in nature. Because it is treatable by only alkaline solution. None 14. An example of a solution which is not in equilibrium is: hypotonic solution anhydrous solution chemical pH indicator supersaturated solution None 15. Product of neutralization reactions are always : a salt and water. an acid and a base an acid and a salt. a salt and a base. None 16. In which of the following, neutralisation reaction takes place? Treatment of acidity Breakdown of glucose All of the above Photosynthesis None 17. What happens to the colour of litmus paper when you put a drop of acid on it? From blue it turns red It is unaffected by acid It gets destroyed From red it turns blue None 18. Which of the following acid is present naturally in the spinach? Citrus acid Tartaric acid Succinic acid Oxalic acid None 19. Using toothpaste in daily life is the example of _________. basic reaction neutralization reaction none of these acidic reaction None 20. Which of the following substance enters our body when a red ant bites us? Melittin Magnesium hydroxide Calcium Formate Formic acid None Time's up Please Share This Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Leave a Reply Cancel replyCommentEnter your name or username to commentEnter your email address to commentEnter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
