C4.1 Acids, Bases and Salts 1. Describe the chemical equation when the hydroxides of Zinc, Aluminum and Lead hydroxide (which are precipitates) reacts with excess sodium hydroxide or potassium hydroxide to form soluble complex ions? Zn(OH)2 (S) + 2OH (aq)- = [ Zn(OH)4]2- colorless Al(OH)2(S) + OH-(aq) = [Al(OH)4] (aq) colorlessPb(OH)2 (S) + 2OH-(Aq) = [Pb(OH)4]2- colorlessAll of the above 2. Aqueous solutions which have a few hydrogen ions are known as? Strong acidsWeak acids Neutral solutionsAll of the above 3. Explain the reason why Sodium Hydroxide is a strong base than the Ammonia solution and what is its effect on electoral conductivity? Sodium hydroxide solutions contain fewer hydroxide ions than ammonia solutionSodium hydroxide solution contains many hydrogen ions than ammonia solutionThe presence of many hydroxide ions in Sodium hydroxide solutions makes it to strongly conduct electricity than ammonia solutionBoth B and C 4. Water hardness that is removed by boiling is known as? PermanentTemporaryContractCasual 5. Mention the metal hydroxide which forms a green precipitate when sodium hydroxide is added onto its solution? Iron (II) hydroxideZinc hydroxideAluminum hydroxideIron (III) hydroxide 6. When Hydrogen Chloride gas dissolves in a polar solvent such as water what will occur It forms a solution that turns a blue litmus paper red.The molecule dissociates in waterPresence of positively charged hydrogen ions and negatively charged chloride ionsAll of the above 7. Hydrochloric acid is a strong acid than Ethanoic acid, what does it mean? Hydrochloric acid has a low pH value and ethanoic acid has a high pH value.Hydrochloric acid has a higher number of hydrogen ionsEthanoic acid has a lower number of hydrogen ionsAll of the above 8. Water hardness that cannot be removed by boiling is called? PermanentTemporaryContractCasual 9. A salt is defined as an ionic compound formed when a cation derived from a base combines with an anion from an acid. True or False FALSETRUEMaybeNone 10. The separation of different salts by making use of the differences in solubility in the same solvent is known as Solvay processFractional distillationFractional crystallization None of the mentioned 11. Which of the following is not an example of a polar solvent from the below list Hydrogen chloride gasWater moleculeMethylbenzeneNone of the mentioned 12. A molecule which behaves as if it is negatively charged in one end and positively charged in the opposite end is said to be? DeliquescentEfflorescentPolar solvent None of the mentioned 13. Explain the reason why Hydrochloric acid has a stronger electrical conductivity than ethanoic acid Presence of fewer hydrogen ions in hydrochloric acidsPresence of higher hydrogen ions in ethanoic acidsPresence of a higher number of hydrogen ions in hydrochloric acid than ethanoic acidNone of the mentioned 14. Mention the metal hydroxide which forms a white precipitate when sodium hydroxide is added onto its solution Magnesium hydroxide and Lead (II) hydroxideZinc hydroxideAluminum hydroxideAll of the above 15. Sodium, Potassium and Ammonium carbonate salts are soluble the rest are all insoluble and form precipitates. True or False FALSEMaybeTRUENone 16. The higher the number of hydroxide ions the higher the pH value and the greater the conductivity in the base solution? True or False FALSEMaybeTRUENone of the mentioned 17. Describe a strong acid in terms of the number of hydrogen ions present and pH value? The higher the number of hydrogen ions the lower the pH value making the solution a strong acidThe fewer the number of hydrogen ions the higher the pH value making the solution a strong acid.The fewer the number of hydrogen ions are the lower the pH value making the solution a strong acidNone of the mentioned. 18. What is the solubility of a solute in a solvent? Is the minimum mass of solute required to saturate a solventIs the maximum mass of solute required to saturate a solventIs the maximum mass of solute required to saturate 100g of solvent at a particular temperatureNone of the mentioned 19. Mention the metal hydroxide which forms a brown precipitate when sodium hydroxide is added onto its solution? Iron (II) hydroxideZinc hydroxideAluminum hydroxideIron (III) hydroxide 20. For most salts solubility increases with? Decrease in temperatureConstant temperatureIncrease in temperature None of the mentioned 21. When Ammonia gas dissolves in a non-polar solvent such as Methylbenzene what will occur? No effect on the litmus paperThe ammonia molecule doesn’t dissociate at allThere is no presence of hydroxide ions in the solutionAll of the above 22. Metal oxides which react with both as acids and bases to form a colorless solution are known as? Polar solventDeliquescentEfflorescentAmphoteric oxides 23. Which of the following statement describes a polar solvent A molecule that behaves as if it is negatively charged in one end and positively charged in the opposite end.Its negative atom in the molecule has a higher ability to attract electrons compared to its positive atom in the molecule e.g. Hydrogen Chloride gasThe solvent is acidic in nature due to the presence of Hydrogen ions.All of the above 24. The hydroxides of Zinc, Aluminum and Lead hydroxide (which are precipitates) react with excess sodium hydroxide or potassium hydroxide to form soluble complex ions. True or False TRUEFALSEMaybeNone 25. A substance that dissociates in water o produce hydroxide as the only negatively charged ions are called? AcidsBasesNeutralNone of the mentioned 26. All metal Sulphates are soluble except Barium and Lead Sulphate which form precipitate. True or False TRUEFALSEMaybeNone 27. Water that contains dissolved salts and does not readily lather with soap is called? Soft waterDistilled waterHard water None of the mentioned 28. Describe the chemical equations when the hydroxides of Zinc and Copper (which are precipitates ) react with excess Ammonia solution to form soluble complex ions Zn(OH)2 (S) + 4NH3 (aq) = [ Zn(NH3)4]2+(aq) + 2OH- (aq)Cu(OH)2 (S) + 4NH3 (aq) = [Cu(NH3)4]2+(aq) + 2OH- (aq) Both B and C None of the mentioned 29. When Hydrogen gas dissolves in a non-polar solvent such as Methylbenzene what will occur No effect on dry litmus paperThe molecule does not dissociate at all.There is no presence of hydrogen ionsAll of the above 30. A precipitate is an insoluble solid that separates out from a solution during a chemical reaction. True or false TRUEFALSEMaybeNone 31. All metal Sulphites are soluble except they react with dilute hydrochloric acid or nitric acid to produce Sulphur (IV) oxide gas. True or Fasle TRUEFALSEMaybeNone 32. Which of the following statement is CORRECT WHEN AN ACID REACTS WITH A BASE? It forms salt and waterThe hydrogen ions from the acid react with the hydroxide ions from the base to form water.NaOH (aq) + HCl (aq) = NaCl (aq) + H2O(l) hence H+ (aq) + OH- = H2O (l) All of the above 33. Water which readily lathers with soap is called Soft water Distilled waterHard water None of the mentioned 34. Mention the metal hydroxide which forms a blue precipitate when sodium hydroxide is added onto its solution? Iron (II) hydroxideZinc hydroxideAluminum hydroxideCopper (II) hydroxide 35. The hydroxides of Zinc and Copper (which are precipitates) react with excess Ammonia solution to form soluble complex ions. True or False FALSEMaybeTRUENone 36. Mention the advantages of hard water? It provides calcium which is essential for strengthening bones 37. Mention the salts which its solubility remains constant with temperature? Sodium ChlorideCalcium SulphateCalcium ethanoateBoth A and B 38. Mention the benefits of complex ions? Used in the industry for softening of hard water as used in ion exchangersUsed in the industry to the extraction of some metals such as aluminum oresChlorophyll and hemoglobin are complex ionsAll of the above 39. When Ammonia gas dissolves in a polar solvent such as water, what will occur? It turns red litmus paper blueAmmonia molecule dissociates and reacts with water to form Ammonium HydroxideThere is the presence of Hydroxide ionsAll of the above 40. The hydroxides of Magnesium (Mg), Zinc (Zn), Aluminum (Al), Iron (II), Iron (III), Copper (Cu) and Lead (II) ions forms a precipitate. True or False FALSEMaybeTRUENone 41. An acid is a substance that dissociates in water to give hydrogen ions as the only positive charged ions. True or False FALSEMaybeTRUENone 42. Mention the disadvantages of hard water? Wastes soapStains white clothes as the soap precipitates out calcium and magnesium ions as scum which forms stain on clothesDeposition of fur (calcium carbonate) in kettles, pipes and boilersAll of the above 43. Which of the following is not an amphoteric oxide Lead oxideZinc OxideAluminum OxidePotassium Oxide 44. All Metal Chloride salts are soluble except Lead (II) ions which are insoluble but in warm water Lead (II) Chloride is soluble. True or False FALSETRUEMaybeNone 45. What occurs when hard water is boiled? Calcium hydrogen carbonate is boiled and precipitates out as Calcium carbonateMagnesium hydrogen carbonate is boiled and precipitates out as Magnesium carbonateThe resulting solutions form lather readily with soap.All of the above 46. Mention the salts which its solubility decrease with temperature? Sodium ChlorideCalcium SulphateCalcium ethanoateNone of the mentioned Loading...
The hydroxides of Magnesium (Mg), Zinc (Zn), Aluminum (Al), Iron (II), Iron (III), Copper (Cu) and Lead (II) ions forms a precipitate. True or False
