This quiz works best with JavaScript enabled. Home > Cbse > Class 7 > Science > Bases > Class 7 Science Chapter 4 Bases – Quiz 8 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 7 Science Chapter 4 Bases Quiz 8 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Calcium phosphate is present in tooth enamel-its nature is A) Amphoteric. B) Neutral. C) Acidic. D) Basic. Show Answer Correct Answer: D) Basic. 2. Which is an example of an amphiprotic species? A) HPO $ _ {4} $$^{2-} $. B) P $ _ {4} $ o $ {10} $. C) At $ _ {2} $ o $ _ {3} $. D) CO$_{3}$$^{2-}$. Show Answer Correct Answer: A) HPO $ _ {4} $$^{2-} $. 3. Guanine bonds with ..... A) Adenine. B) Thymine. C) Guanine. D) Cytosine. Show Answer Correct Answer: D) Cytosine. 4. What is an important safety consideration when handling concentrated alkalis? A) Always add water directly to concentrated alkalis. B) The reaction between alkali and water is exothermic, so care must be taken when adding alkali to water. C) Alkalis should always be mixed with acids. D) Concentrated alkalis can be safely handled without gloves. Show Answer Correct Answer: B) The reaction between alkali and water is exothermic, so care must be taken when adding alkali to water. 5. Alum acts as an antacid. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 6. In a BD, objects at a higher level, where information is stored. A) Tables. B) Records. C) Ranks. D) Campos. Show Answer Correct Answer: A) Tables. 7. What are the products when hydrobromic acid is mixed with sodium hydroxide A) H$_{2}$O and NaBr. B) HBr and NaOH. C) OBr and NaH. D) BrOH. Show Answer Correct Answer: A) H$_{2}$O and NaBr. 8. The root phono (from Greek) means "sound." Megaphones are used by cheerleaders, police officers or someone speaking to a large crowd.A telephone lets you hear the voices of people who are far away.If the root "caco" means "bad, " a "cacophonous" piece of music most likely A) Sounds terrible, like screeching cats. B) Is too quiet to hear clearly. C) Has an upbeat, fast tempo. D) Was written by a bad person. Show Answer Correct Answer: A) Sounds terrible, like screeching cats. 9. Acids release ..... A) H$^{+}$. B) OH$^{-}$. C) H$_{2}$. D) None of the above. Show Answer Correct Answer: A) H$^{+}$. 10. What is the formula of calcium oxide? A) Ca $ _ {2} $ o. B) Ca $ _ {2} $ o $ _ {2} $. C) CaO$_{2}$. D) CaO. Show Answer Correct Answer: D) CaO. 11. According to Bronsted-Lowry acid base theory, an acid is a ..... A) Made of H+. B) Proton donor. C) Proton acceptor. D) Produces H+ when added to water. Show Answer Correct Answer: B) Proton donor. 12. Does not react with red litmus paper leaving it red A) Acid. B) Base. C) Neutral. D) None of the above. Show Answer Correct Answer: A) Acid. 13. What is the meaning of the Greek base 'auto'? A) Self. B) Heat. C) Time. D) Earth. Show Answer Correct Answer: A) Self. 14. If there is combined 60% for Cytosine and Guanine, what is the combined % for Adenine and Thymine? A) 40%. B) 60%. C) 20%. D) 10%. Show Answer Correct Answer: A) 40%. 15. Which of the following monomers are repeatedly joined together to form a strand of DNA? A) Nucleotides. B) Polysaccharides. C) Fatty acids. D) Amino acids. Show Answer Correct Answer: A) Nucleotides. 16. The following neutralization reaction occurs in the classroom.HCl + KOH $\rightarrow$ H$_{2}$O + KClIf a student uses 25.0 mL of a 0.5M solution of KOH, what is the molarity of the acid if 15.0mL of acid neutralized? A) 0.8M. B) 1.M. C) 12. D) None of the above. Show Answer Correct Answer: A) 0.8M. 17. A century is ..... years. A) Ten. B) One hundred. C) One thousand. D) Ten thousand. Show Answer Correct Answer: B) One hundred. 18. Which one of the following is NOT a property of acids. A) Conduct electricity. B) Corrodes metals. C) Tastes sour. D) Turns red litmus paper blue. Show Answer Correct Answer: D) Turns red litmus paper blue. 19. What millennium is the year-2465 the year? A) -Ier millennium. B) -millennium. C) -Ave millennium. D) -millennium. Show Answer Correct Answer: B) -millennium. 20. It indicates the relative force, as an acid, for a substance. A) Arrhenius Theory. B) TEORIA DE BRONSTED-LOWRY. C) N.A. D) Hydrogen ion index (pH). Show Answer Correct Answer: D) Hydrogen ion index (pH). 21. A sour taste is a characteristic of: A) PH scale. B) Neutral. C) Bases. D) Acids. Show Answer Correct Answer: D) Acids. 22. The sequence of nitrogenous bases in DNA varies widely. The sequence of the bases in DNA is most important for which of the following? A) Providing the instructions for the traits of an organism. B) Preventing mutations from occuring during RNA replication. C) Allowing the DNA to have the shape necessary for replication. D) Helping form the sugar-phosphate backbone of DNA molecules. Show Answer Correct Answer: A) Providing the instructions for the traits of an organism. 23. What century is the year 1769? A) XVIIth century. B) 20th century. C) 18th century. D) 21st century. Show Answer Correct Answer: C) 18th century. 24. The age element within the databases is: A) Entity. B) Attribute. C) Valor. D) None of the above. Show Answer Correct Answer: B) Attribute. 25. The indicator litmus is added to a solution with a pH of 3.8 what color will it turn? A) Blue. B) Yellow. C) Red. D) Orange. Show Answer Correct Answer: C) Red. 26. Acids are stored in glass or metallic containers? Why? A) Metal Container because it increases the effect while doing a test. B) Glass Containers because the chemicals present in glass helps to emerge the colour more properly while doing a test. C) Metals as they would preserve the acid for a long time, increasing the effect. D) Glass containers because metals react with acids if acids are stored in metallic containers. Show Answer Correct Answer: D) Glass containers because metals react with acids if acids are stored in metallic containers. 27. What base pairs with adenine? A) Cytosine. B) Phosphate. C) Thymine. D) Guanine. Show Answer Correct Answer: C) Thymine. 28. Thermometer comes from the Greek therm meaning "heat" and meter meaning "measure." What does thermometer mean? A) A device used to measure height. B) A device used to monitor progress. C) A device used for measuring temperature. D) A device used to heat up the body. Show Answer Correct Answer: C) A device used for measuring temperature. 29. H+ and Oh ions when the substance called: A) Agua. B) Hydride. C) Hydroxide. D) None. Show Answer Correct Answer: A) Agua. 30. Sodium bicarbonate is a substance: A) Acidic. B) Neutral. C) Basic. D) None of the above. Show Answer Correct Answer: C) Basic. 31. Is it possible to have databases without tables related to each other? A) Yes, because the information can be accessed from the forms. B) No, because there are dependent tables that necessarily require information from other tables. C) All the above. D) None of the above. Show Answer Correct Answer: B) No, because there are dependent tables that necessarily require information from other tables. 32. Identify the base from the following compounds: A) $H_2SO_4$. B) $NH_3$. C) $CO_2$. D) $H_2O$. Show Answer Correct Answer: B) $NH_3$. 33. HCO$_{3}$$^{-}$ + H$_{2}$O $\rightarrow$ H$_{3}$O$^{+}$ + CO$_{3}$$^{2-}$Water is acting as A) A Bronsted Lowry acid. B) A strong acid. C) A Bronsted Lowry base. D) A weak acid. Show Answer Correct Answer: C) A Bronsted Lowry base. 34. Which of these is a base? A) Nitric acid. B) Sodium hydroxide. C) Hydrocloric acid. D) Bromothymol blue. Show Answer Correct Answer: B) Sodium hydroxide. 35. The latin root mater means A) Father. B) To look. C) Mother. D) To make. Show Answer Correct Answer: C) Mother. 36. Prejudice and judicial contain the latin root jud that means A) To send. B) Judge. C) Good. D) Water. Show Answer Correct Answer: B) Judge. 37. Weaker Bases have a pH closer to 7 A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 38. What is the value of 1203$_{4}$? A) 67. B) 54. C) 48. D) 99. Show Answer Correct Answer: D) 99. 39. Acids will neutralize a base, and bases will neutralize acids. If you add a base to a solution containing a strong acid, what will happen to the pH of the solution? A) The pH will increase. B) The pH will decrease. C) The pH will stay the same. D) None of the above. Show Answer Correct Answer: A) The pH will increase. 40. If there are 5 red sour patch out of 20 total sour patch, what percent are red? A) 25%. B) 15%. C) 20%. D) 30%. Show Answer Correct Answer: A) 25%. 41. What is the pH range of acids? A) 0 to 14. B) 7 to 10. C) 7 to 14. D) 0 to 7. Show Answer Correct Answer: D) 0 to 7. 42. What is the pH range of a basic solution? A) 8-14. B) 0-3. C) 4-6. D) 7. Show Answer Correct Answer: A) 8-14. 43. Carbonic acid is present in ..... A) Baking powder. B) Lemon juice. C) Tomato. D) Soft drinks. Show Answer Correct Answer: D) Soft drinks. 44. What is the name of the base with the formula $Ca(OH)_2$ A) Calcium hydroxide. B) Calcium oxide. C) Calcium hydride. D) Calcium carbonate. Show Answer Correct Answer: A) Calcium hydroxide. 45. What is the role of a base in a neutralization reaction? A) It accepts protons. B) It releases hydrogen gas. C) It forms a precipitate. D) It donates protons. Show Answer Correct Answer: A) It accepts protons. 46. What are the proper complementary base-pairs? A) A T and G C. B) A G and C T. C) G T and A C. D) A C and T G. Show Answer Correct Answer: A) A T and G C. 47. Which molecules forms the sides (backbone) of the DNA ladder? A) Sugars. B) Nitrogen bases. C) All of these. D) Phosphates. Show Answer Correct Answer: D) Phosphates. 48. Which of the following solutions would be a weak alkali? A) Sodium hydroxide (NaOH). B) A solution of sodium hydroxide where less than 30% of molecules dissociate. C) Calcium hydroxide in excess of water. D) Potassium hydroxide (KOH). Show Answer Correct Answer: B) A solution of sodium hydroxide where less than 30% of molecules dissociate. 49. Example:purified water A) Acid. B) Base. C) Neutral. D) None of the above. Show Answer Correct Answer: C) Neutral. 50. How many nucleotide bases are there? A) 4. B) 2. C) 3. D) 1. Show Answer Correct Answer: A) 4. 51. Which of the following are found in RNA but not in DNA? A) Deoxyribose sugar and thymine. B) Ribose sugar and thymine. C) Ribose sugar and uracil. D) Deoxyriboce sugar and uracil. Show Answer Correct Answer: C) Ribose sugar and uracil. 52. Which of the following latin roots means one hundred? A) With. B) Port. C) Cent. D) Bene. Show Answer Correct Answer: C) Cent. 53. What PH number would be an example of a strong acid? A) 14. B) 7. C) 13. D) 1. Show Answer Correct Answer: D) 1. 54. Some bases present in their names, numbers written in Roman numerals, therefore: A) Chemistry likes to make my life difficult. B) Because there are elements that have variable load. C) All bases need this number in Roman digit. D) None of the above. Show Answer Correct Answer: B) Because there are elements that have variable load. 55. How do nitrogen bases contribute to the genetic code? A) By forming the backbone of the DNA strand. B) By determining the sequence of amino acids in proteins. C) By providing energy for cellular processes. D) By acting as catalysts in biochemical reactions. Show Answer Correct Answer: B) By determining the sequence of amino acids in proteins. 56. What is the formula of ammonia? A) NH$_{3}$. B) H$_{2}$O. C) H$_{2}$. D) CO$_{2}$. Show Answer Correct Answer: A) NH$_{3}$. 57. A substance with a pH of 6 is A) A base. B) An acid. C) Neutral. D) None of the above. Show Answer Correct Answer: B) An acid. 58. A student is studying a substance that tastes bitter and is slippery to touch. When phenolpthalein is added is turns magenta. What is the student most likely studying? A) Water (neutral). B) Lemon juice (acid). C) Salt solution (neutral). D) Drain cleaner (base). Show Answer Correct Answer: D) Drain cleaner (base). 59. The range of less than 7 to zero corresponds to substances with character ..... A) Redox. B) Acid. C) Basic. D) Salado. Show Answer Correct Answer: B) Acid. 60. Ascientisttestsasoilsamplefromanuncultivated fieldandconcludesthatthesoilishighly basicinnature.Shesuggests thataddingorganicmatterinthesoilcouldimprovethequalityofthe soil.Howdoesorganicmatterimprovethequalityofthesoil? A) Ittrapswatervaporandincreasesthemoisturecontent. B) Itreleasesacidswhichneutralizesthesoil. C) Itmakesthesoillightersothatitcanbeeasilytransported. D) Itactsasfoodfortheorganismsalreadypresentinthesoil. Show Answer Correct Answer: B) Itreleasesacidswhichneutralizesthesoil. ← PreviousNext →Related QuizzesScience QuizzesClass 7 QuizzesClass 7 Science Chapter 4 Bases Quiz 1Class 7 Science Chapter 4 Bases Quiz 2Class 7 Science Chapter 4 Bases Quiz 3Class 7 Science Chapter 4 Bases Quiz 4Class 7 Science Chapter 4 Bases Quiz 5Class 7 Science Chapter 4 Bases Quiz 6Class 7 Science Chapter 4 Bases Quiz 7Class 7 Science Chapter 4 Bases Quiz 9 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books