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