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