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. Which pair of indicators shows no colour change when used with acidic solutions? China rose and phenolphthalein Litmus and China rose Turmeric and China rose Turmeric and phenolphthalein None 2. One of the following that does not inject an acidic liquid into the skin through its sting. This is Honey bee Wasp Nettle leaf hair Ant None 3. Which of the following set of substances contain acids only? Grapes, lime water Curd, vinegar Vinegar, soap Curd, milk of magnesia None 4. Which base is employed as the electrolyte in alkaline batteries? Al(OH)3 KOH FeOH NaOH None 5. 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. C and B A and D A and C B and D None 6. The acid used in the making of vinegar is: acetic acid nitric acid sulphuric acid formic acid None 7. Which of the following acid is present in the sting of an ant? Formic acid Succinic acid Tartaric acid Oxalic acid None 8. Phenolphthalein is a synthetic indicator and its color in acidic and basic solutions, respectively are: blue and red pink and colorless colorless and pink red and blue None 9. 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 10. Milk of magnesia Mg(OH) 2 is a/an: acid rock salt alkali antacid None 11. Which of the following is a use of sodium hydroxide? It is an important constituent of drain cleaners. It is used in the manufacture of soaps and paper. It is used in the manufacture of synthetic fibers like rayon. All of the above. None 12. 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. II IV III I None 13. An aqueous solution turns red litmus blue. Excess addition of which of the following solutions would reverse the change? Water Ammonium hydroxide solution None of these Hydrochloric acid None 14. 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 15. To protect tooth decay we are advised to brush our teeth regularly. The nature of the toothpaste commonly used is: Neutral Corrosive Acidic Basic None 16. Which of the following set of substances contain acids only? Curd, milk of magnesia Grapes, lime water Curd, vinegar Vinegar, soap None 17. Which substance when dissolved in water changes red litmus paper to blue. Tooth paste Milk of magnesia Shower cream All of the above None 18. In which of the following chemical processes does the reaction mixture become hot? Mixing two samples of an acid Evaporating liquid water Mixing two samples of a base Neutralisation of an acid with a base None 19. Which one of the following types of medicines is for treating indigestion ? Antiseptic Antibiotic Analgesic Antacid None 20. 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 in removing stains of grease from cloths It is used as an antacid 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.