FBQ1: Because of the intense colouration of_______ it is very difficult to read the meniscus of the solution in burette. Answer: KMnO4 FBQ2: The potassium permanganate solution intended for______ must be standardised prior to use. Answer: redox titration FBQ3: A standard solution of Oxalic acid is a hydrated _____ that can be obtained in high purity in the laboratory. Answer: dibasic acid FBQ4: Oxidation-reduction reactions are reactions in which ______ are transferred from one ion to another Answer: electrons FBQ5: Oxidation-reduction reactions are also used in ----------- like the acid-base reactions Answer: titrimetric analysis FBQ6: In redox titration involving potassium permanganate, if the contents of the conical flask turn brown, it means that _____ was added. Answer: Insufficient acid catalyst FBQ7: The equation for the redox reaction is, X (aq) + 5C2O42-(aq) +16H+(aq)→ 2Mn2+(aq) + 10CO2(g)+8H2O(l). Identify the reactant X.  Answer: MNO-4 FBQ8: From the equation MNO-4(aq) + 5C2O42-(aq) +16H+(aq) the mole ratio between the reactant is____ Answer: 5moles FBQ9: Potassium permanganate is a self-indicating reagent because of its different characteristic _______ in either the acidic or basic medium Answer: Colour changes FBQ10: Potassium permanganate can be used to estimate the ________of a substance. Answer: percentage purity FBQ11: IO32- + SO32+ ­­→ I +SO42- The oxidation state of oxygen in the product’s equation is______ Answer: +6 FBQ12: IO32- + SO32+ the oxidation state of oxygen in the equation is ______  Answer: +4 FBQ13: CO + H2SO4 → CO2 + SO2 + H2O The elements which undergo change in oxidation state from the reactants to the products are_________  Answer: C and S FBQ14: Volumetric analysis involving iodine are usually referred to as ___________ Answer: Iodimetry FBQ15: In the _____, standard solutions of iodine are used to estimate directly the concentrations of some oxidizable species. Answer: Direct method FBQ16: In the ________ the excess iodine ion that is deliberately produced in a reaction involving say potassium iodide in an acid medium is made to react with another oxidizing agent. Answer: indirect method FBQ17: 2I-(aq)→I2(aq) +2e-. In this equation the liberated I2 is now quantitatively determined by titration with standard _________solution acting as reducing agent according to the equation below.2S2O32- (aq) + I2(aq) → S4O62-(aq) + 2I-  Answer: Sodium thiosulphate FBQ18: Of all the oxidizable species available for use, iodine titration are usually used with the___ Answer: thiosulphate FBQ19: The colour changes accompanying the varying change in oxidation states of iodine and its ion can be used to indicate the________ Answer: end point FBQ20: The most commonly used __________for iodine titration is starch solution. Answer: external indicator FBQ21: The starch solution forms a _______complex with the tri-iodide ion during the titration that is rapidly discharged at the end point. Answer: blue black **FBQ22: Thus using starch as indicator, the colour variations of the solution depend on ______formation of the starch with iodide ion formed in the last stage of the titration. Answer: complex **FBQ23: For this reason and in order to avoid complications in the end point detection, the starch indicator is added at the______ colouration of the solution which is near the end point. Answer: light yellow **FBQ24: Complete the colour change in iodometry analysis. _______(initially)→ Answer: Red-brown FBQ25: _______ colouration is observed at near end point of the iodometry titration. Answer: Light yellow FBQ26: Oxidation involves the-------------of electrons Answer: lost *8FBQ27: The oxidation potentials of Na is________ Answer: Na+ + e +2.71 FBQ28: The study of thermal changes in chemical and physical processes is known as________ Answer: thermochemistry FBQ29: The _________is the amount of heat released or observed for a given amount of reactants or products Answer: heat of reaction FBQ30: The only acid suitable for use in redox titration involving potassium permanganate is dilute_________ Answer: Sulphuric acid FBQ31: Nitric acid would compete with the permanganate ion for the reducing agent because itself is a __________ Answer: strong oxidizing agent FBQ32: Reduction reaction involves -------- of electrons Answer: gain FBQ33: Oxidation-reduction reactions involves a change in ------------- of both substances being determined Answer: oxidation state FBQ34: Unlike acid-base reactions, redox procedure involves the use of-------------- Answer: Catalyst or slight heat FBQ35: When atoms of elements are in their free state their oxidation number is-------- Answer: zero MCQ1: In preparing a standard solution, two factors must be considered, namely: Answer: 1.The solute must be pure 2. The suitable solvent should be measure to a definite volume MCQ2: A solution contains 1.2 Molar concentration, what volume of it must be diluted with water to give 600 mls of 0.5 Molar solution? Answer: 25 mls MCQ3: In a chemistry laboratory a stoke bottle of acid solution reads, “1.25 specific gravity”; what does that mean? Answer: 1 cm3 of that solution weight 1.25 g MCQ4: If 2 cm3 of a stoke solution contains 1 mole of an acid how would you prepare 1 molar concentration of that acid in 250 cm3 of water? Answer: Dissolve 2 cm3 of the stoke solution in 248 cm3 of water MCQ5: A substance which loses water of hydration upon exposure to atmosphere is called? Answer: Efflorescence substance MCQ6: A substance which takes in only moisture upon exposure to atmosphere is referred to as? Answer: Deliquescent substance MCQ7: A table of requirement for laboratory experiment contains the following except? Answer: List of weight of each reagents **MCQ8: Give reason why water should not be added to acid during carrying out acid-base titration? Answer: The dissolution of acid in water is exothermic which may cause explosion MCQ9: The concentration of pure HCl 11.7 Molar if 20 cm3 of the acid is diluted to 250 cm3 to give concentration of 0.936 mol.dm3 substitute this values on this equation; CIVI=C2V2? Answer: 11.7 X 20 = 0.936 X 250 MCQ10: The point at which stoicheometrically equivalent quantities of substance have been brought together is known as? Answer: Equivalence point of titration MCQ11: Which of the following options is an indicator used for acid-base titration? Answer: Methyl orange MCQ12: In an acid base titration conducted by a student, the colour of the solution in the beaker changed from colourless to pink when phenolphthalein was used as an indicator, what went wrong? Answer: The beaker was occupied by acid solution instead of base. MCQ13: What is a PH of a solution? Answer: It is the measure of hydrogen ions concentration in the solution MCQ14: At neutralization point, the PH value is? Answer: Seven MCQ15: At complete neutralization point, the litmus paper colour turns? Answer: Purple MCQ16: Predict the colour of methyl orange when pH is 8? Answer: Yellow MCQ17: What is the colour of bromothymol when added to an acid solution? Answer: Yellow MCQ18: An indicator X was added to an acid solution in a beaker but no colour change was observed give the name of the indicator X? Answer: Phenolphthalein MCQ19: What is a strong acid? Answer: Any acid that ionizes completely in solution MCQ20: An example of a strong acid is? Answer: H2SO4 MCQ21: What type of indicator will be suitable for use in a titration involving H2SO4 + NH3(ag)? Answer: Methyl orange MCQ22: Which of these indicators will be suitable for use in a titration involving a weak acid and a strong base? Answer: Phenolphthalein MCQ23: What is the implication of adding a phenolphthalein as an indicator during the titration of HCl against Na2CO3? Answer: The end point will appear when only half of Na2CO3 has been used MCQ24: What is the importance of back titration? Answer: To determine the concentration of a substance that is in excess after a chemical reaction. **MCQ25: A 25 ml solution of 0.5 M NaOH is titrated until neutralized into a 50 ml sample of HCl? Answer: 0.25 mol MCQ26: A student used a hard tap water and performed and acid base titration. In few lines explain what would happen to his result? Answer: the starting solution would be more alkaline therefore it would require more volume of acid than expected MCQ27: Choose the most suitable water for use in acid base titration? Answer: Deionised water MCQ28: Both molarity and normality are measures of concentration. True or false? Answer: True MCQ29: During acid-base titration sulphuric acid would be dissociated into what ions? Answer: 2H+ + SO4- MCQ30: What is a titrand in titration anlysis? Answer: Unknown concentration of an analyte MCQ31: What is a titrant in titration analysis? Answer: Known concentration and volume of an analyte MCQ32: Which of these is a method of finding the equivalence point? Answer: All of the options MCQ33: When performing acid-base titration, one should first? Answer: Rinse the burette twice with acid solution MCQ34: The equation NaOH + HCl →NaCl + H2O is a ____? Answer: Neutralization reaction MCQ35: The following are advantages of acid base titration except? Answer: Less accuracy and precision