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