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. 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 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 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 2. Which of the following acid is present naturally in the spinach? Citrus acid Tartaric acid Oxalic acid Succinic acid None 3. 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 (iii) only (i), (ii) and (iii) (i) and (iii) only None 4. 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 turns blue and blue litmus turns red. Red litmus remains red and blue litmus turns red. Red litmus turns blue and blue litmus remains blue. None 5. Which of the following substance enters our body when a red ant bites us? Calcium Formate Magnesium hydroxide Melittin Formic acid None 6. A solution changes the colour of turmeric paper from yellow to red. The solution is: neutral basic acidic either neutral or acidic None 7. Which of the following is not a property of acid? Acid turns blue litmus to red. Acids change the colour of turmeric None of these Acids are sour in taste None 8. Which one of the following will turn blue-litmus red? Washing soda solution Vinegar Lime water Baking soda solution None 9. Why bee strings are treated by alkaline solutions? None of these. Because it is basic in nature Because it is treatable by only alkaline solution. Because it is acidic in nature. None 10. When honeybee bites, which chemical enters in to our body? Melittin Magnesium hydroxide Formic acid Calcium formate None 11. In which of the following, neutralisation reaction takes place? All of the above Treatment of acidity Breakdown of glucose Photosynthesis None 12. An example of a solution which is not in equilibrium is: anhydrous solution chemical pH indicator supersaturated solution hypotonic solution None 13. The colour of pH paper strip at the pH valued of 1,7 and 14 will be : Green, blue and red Blue, green and red Red, green and blue Green, red and blue None 14. What happens to the colour of litmus paper when you put a drop of acid on it? From red it turns blue It gets destroyed It is unaffected by acid From blue it turns red None 15. From which plant is litmus paper or litmus solution obtained? Hibiscus Moss Rose Lichen None 16. Using toothpaste in daily life is the example of _________. none of these acidic reaction basic reaction neutralization reaction None 17. Turmeric is a natural indicator. On adding its paste to acid and base separately, which colour would be observed ? Yellow in acid and red in base Yellow in both acid and base Red in acid and blue in base Pink in acid and yellow in base None 18. Honey bee stings and ant bites can be _________ using alkaline medicine such as baking powder. Prevented Neutralize None of the above Acidifies None 19. Product of neutralization reactions are always : a salt and a base. a salt and water. an acid and a salt. an acid and a base None 20. China rose is which type of indicator? Olfactory indicator Synthetic indicator None of the above Natural indicator 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.
