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