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. Which of the following is not a property of acid? None of these Acids change the colour of turmeric Acids are sour in taste Acid turns blue litmus to red. None 2. Turmeric is a natural indicator. On adding its paste to acid and base separately, which colour would be observed ? Red in acid and blue in base Pink in acid and yellow in base Yellow in acid and red in base Yellow in both acid and base None 3. Which one of the following will turn blue-litmus red? Washing soda solution Baking soda solution Lime water Vinegar None 4. 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) only (i), (ii) and (iii) (iii) only (i) and (iii) only None 5. Using toothpaste in daily life is the example of _________. none of these neutralization reaction basic reaction acidic reaction None 6. Honey bee stings and ant bites can be _________ using alkaline medicine such as baking powder. None of the above Neutralize Prevented Acidifies None 7. Which of the following acid is present naturally in the spinach? Oxalic acid Citrus acid Succinic acid Tartaric acid None 8. An example of a solution which is not in equilibrium is: anhydrous solution hypotonic solution supersaturated solution chemical pH indicator None 9. Product of neutralization reactions are always : an acid and a salt. an acid and a base a salt and water. a salt and a base. None 10. When honeybee bites, which chemical enters in to our body? Formic acid Calcium formate Magnesium hydroxide Melittin None 11. Why bee strings are treated by alkaline solutions? Because it is basic in nature Because it is treatable by only alkaline solution. Because it is acidic in nature. None of these. None 12. The colour of pH paper strip at the pH valued of 1,7 and 14 will be : Green, red and blue Red, green and blue Blue, green and red Green, blue and red None 13. From which plant is litmus paper or litmus solution obtained? Lichen Rose Hibiscus Moss None 14. A solution changes the colour of turmeric paper from yellow to red. The solution is: neutral either neutral or acidic acidic basic None 15. In which of the following, neutralisation reaction takes place? Treatment of acidity Photosynthesis Breakdown of glucose All of the above None 16. What do we observe on pouring acetic acid on red and blue litmus paper? Red litmus remains red and blue litmus turns red. Red litmus turns blue and blue litmus remains blue. Red litmus becomes colourless and blue litmus remains blue Red litmus turns blue and blue litmus turns red. None 17. 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: 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 there is no change in the red litmus paper and the blue litmus paper turns red there is no change in the blue litmus paper and the red litmus paper turns white None 18. China rose is which type of indicator? Natural indicator Olfactory indicator Synthetic indicator None of the above None 19. Which of the following substance enters our body when a red ant bites us? Melittin Formic acid Magnesium hydroxide Calcium Formate None 20. What happens to the colour of litmus paper when you put a drop of acid on it? From red it turns blue It is unaffected by acid It gets destroyed From blue it turns red 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.
