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