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