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