Ncert- science – class 7- Chapter 4 – Acids, Bases and Salts 2 Welcome to your Ncert- science - class 7- Chapter 4 – Acids, Bases and Salts 2 1. An aqueous solution turns red litmus blue. Excess addition of which of the following solutions would reverse the change? Water None of these Hydrochloric acid Ammonium hydroxide solution None 2. Manisha took a little bit of soil from her garden and mixed it with water. When she dipped a blue litmus in it, the litmus turned red. By adding which of the following to her garden will she get better plant growth? Water Salt Slaked lime Hydrochloric acid None 3. Which of the following is a use of Al(OH)3 It is used in fire extinguisher as a foaming agent It is used in the preparation of fertilizers It is used as an antacid It is used in removing stains of grease from cloths None 4. Which base is employed as the electrolyte in alkaline batteries? KOH FeOH Al(OH)3 NaOH None 5. Phenolphthalein is a synthetic indicator and its color in acidic and basic solutions, respectively are: red and blue blue and red colorless and pink pink and colorless None 6. Milk of magnesia Mg(OH) 2 is a/an: alkali antacid rock salt acid None 7. A drop of a liquid sample was put on the pH paper. The color of the pH paper turned blue. The liquid sample could be that of: Hydrochloric acid Ethanoic acid Sodium bicarbonate solution Lemon juice None 8. Which of the following set of substances contain acids only? Curd, vinegar Vinegar, soap Curd, milk of magnesia Grapes, lime water None 9. Which substance when dissolved in water changes red litmus paper to blue. Milk of magnesia Tooth paste All of the above Shower cream None 10. Which of the following is a use of sodium hydroxide? All of the above. It is used in the manufacture of soaps and paper. It is used in the manufacture of synthetic fibers like rayon. It is an important constituent of drain cleaners. None 11. In which of the following chemical processes does the reaction mixture become hot? Evaporating liquid water Mixing two samples of an acid Mixing two samples of a base Neutralisation of an acid with a base None 12. Which one of the following types of medicines is for treating indigestion ? Analgesic Antacid Antiseptic Antibiotic None 13. Which of the following acid is present in the sting of an ant? Formic acid Tartaric acid Succinic acid Oxalic acid None 14. One of the following that does not inject an acidic liquid into the skin through its sting. This is Nettle leaf hair Ant Honey bee Wasp None 15. The acid used in the making of vinegar is: formic acid nitric acid acetic acid sulphuric acid None 16. In an experiment to test the pH of a given sample using pH paper, four students recorded the following observations :SamplepH Paper ColorWaterBlueDilute HClRedDilute NaOHBlueDilute Ethanoic AcidOrange Which one of the above observations is incorrect. I III IV II None 17. Which pair of indicators shows no colour change when used with acidic solutions? China rose and phenolphthalein Litmus and China rose Turmeric and phenolphthalein Turmeric and China rose None 18. Which of the following set of substances contain acids only? Curd, milk of magnesia Grapes, lime water Curd, vinegar Vinegar, soap None 19. To protect tooth decay we are advised to brush our teeth regularly. The nature of the toothpaste commonly used is: Basic Acidic Corrosive Neutral None 20. On washing with soap, a turmeric stain on the cloth turns to red becauseA. soap solution is alkaline.B. soap solution is acidic.C. turmeric contains a natural indicator.D. turmeric contain litmus.Select the correct alternative. A and D B and D A and C C and B 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.