Question: When acid is spilled in the laboratory it should be Answer:Neutralised with sodium bicarbonate Question: One of the disadvantage of wearing loose sleeves to the laboratory during a practical class is Answer:They can sweep flasks from the laboratory bench Question: Smoking is prohibited in the laboratory because o Answer:It can cause fire hazard Question: Which of the following should not be used to put off a chemical fire Answer:Water Question: Glassware are used for experiments in the Chemistry laboratory because Answer:They are relatively inert transparent and more heat resistant Question: Darkened brown or amber glass is used to Answer:Keep out much of UV and IR radiation Question: Which of the following is used for measuring liquids by volume Answer:Graduated cylinder Question: Spilled base should be Answer:Neutralised with dilute acetic acid Question: is used to remove water or solvents of relatively low boiling point adhering to solids under reduced pressure at room temperature or to keep anhydrous compounds Answer:Vacuum dessicators Question: Separatory funnel is used to separate Answer:Two immiscible liquids Question: Which of the following is not a separation technique frequently employed in the laboratory to isolate one or more components from a mixture Answer:Crystallography Question: A solid is said to melt sharply if the melting oint range is Answer:05 10 degree centigrade Question: The reading of a cold object weighed on a balance will be than it will be after it warms up to room temperature Answer:Higher Question: bonds are broken during a change from the liquid phase to the gas phase Answer:Dipole dipole interactions Question: Extraction is used for the separation of materials that are in nature Answer:Liquid and solid Question: Which of these statement is true Answer:Simple distillation involves one cycle of vaporisation condensation Question: Amongst the glassware listed below is the most precise and accurate method of transferring and delivering liquids Answer:Graduated cylinders Question: Extraction is carried out by shaking the solution with a second solvent that is with the one in which the compound is dissolved Answer:Immiscible Question: provides a large surface area in which the initial distillate is redistilled and condensed again Answer:Fractionating column Question: is the most common extraction solvent Answer:Ethyl ether Question: Q1 When identify gases it is advised that you hold your nose directly over the vessel from which the gas is coming from Answer: false Question: Q2 ------------ is constructed so that it is possible to measure and deliver accurate volumes Answer: Burette Question: Q3 The apparent downward curvature of the liquid mainly due to surface tension is called Answer: Lower meniscus Question: Q4 Which apparatus is used to give most precise voume measurements? Answer: Volumetric glassware Question: Q5 -------------- are used to place and heat small quantities of substance to very high Answer: Crucibe Question: Q6 Which of the foowing is not a not a part of bunsen burner? Answer: Gas inlet Question: Q7 Apparatus used to support glasswares on a ring stand are called Answer: Clamp Question: Q8 During wheighing, samples are usually placed on Answer: Watch glass Question: Q9 Identify the tye of condenser used for cooling evaporating sovents Answer: Lie-big condenser Question: Q10 Buchner funnel is used in Answer: Vacuum filteration Question: Q11 Quartz glass is used for its ability to withstand high temperatures Answer: true Question: Q12 The folowing are example of laboratory flasks except Answer: Measuring flask Question: Q13 Electronic balance is primariy used for Answer: Measuring weights Question: Q14 All of the foowing are glasswares except Answer: Buchner funnel Question: Q15 Which of the foowing is not a function of glasswares? Answer: Storing chemicals Question: Q16 Extremely corrosive substances like hydrofluoric acid are handled in Answer: Glass containers Question: Q17 One of the main advantage of using glass apparatus is Answer: Ductility Question: Q18 The type of storage apparatus needed for protection against UV or IR radiations is Answer: Dark brown or amber Question: Q19 Borrosilictaes glasses are used because they are Answer: Thermaly stable Question: Q20 ---------Refers to a variety of equipment, traditionally made of glass, used for scientific experiments Answer: Calorimeters Question: Q21 The following are forces of attraction exists between and are responsible for holding liquid molecules together except Answer: Covalent Question: Q22 All the following can have effect on boiing points except Answer: Concentration Question: Q23 Boiling point measurement can used as qualitative method of identification Answer: true Question: Q24 Density can be measured through the following ways except Answer: Thermometer Question: Q25 A mixture containing miscible liquids that can mimic the boiling behaviour of pure liquids is called Answer: Azeotrope Question: Q26 The quantity expressed as mass per unit volume is known as Answer: Density Question: Q27 A cube of copper was found to have a mass of 0.630 kg. What is the volume of the cube? (The density of copper is 8.94 g/cm3). Answer: 70.47 cm3 Question: Q28 The following are example of solvents used in extraction except Answer: Water Question: Q29 All the following are desirable properties of an organic extraction solvent except Answer: It must have higher boiling point Question: Q30 Which of the following does not have effect on distillation process? Answer: Concentration Question: Q31 The advantage of dichloromethane over ethyl ether is Answer: Inflammability Question: Q32 A common aplication of distillation process is Answer: Sieving Question: Q33 The main advantage of using ethyl ether as the most common solvent is Answer: very low boiling point and better solublity Question: Q34 A solvent to be used to extract an organic compound from aqueous mixture or solution must be Answer: insoluble in water with low boilling point Question: Q35 Distillation is used to separate the mixture of Answer: Miscible liquid Question: Q36 The larger the value of Kd, the better the separation Answer: true Question: Q37 The ratio of the concentration of the solute in each solvent at equilibrium is a constant called Answer: distribution ratio Question: Q38 The major aparatus used in the extraction of organic subtances in the laboratory is Answer: Separatory funnel Question: Q39 The main technical principle on which the extraction process is based on is called Answer: Equilibrium distribution Question: Q40 -------------is a separation technique frequently employed in the laboratory to isolate one or more components from a mixture Answer: Extaraction Question: Q41 --------------is the separation between two distinct phases; immiscible liquids Answer: Partitioning Question: Q42 Purification of solid products mixture is performed to remove by-products and impurities through Answer: Crystallisation Question: Q43 Which of the following aparatus is not used in recrystallisation? Answer: stirring rod Question: Q44 Which apparatus is used to give most precise voume measurements? Answer: Volumetric glassware Question: Q45 A mixture containing miscible liquids that can mimic the boiling behaviour of pure liquids is called Answer: Azeotrope Question: Q46 The main difference in exerimental set up between simple and factional distillation is Answer: The use of frationating column Question: Q47 When there is need to separate a mixture of several miscible liquids which method is appropriate? Answer: Fractional distillation Question: Q48 The law which states that in an ideal solution, the partial pressure (Pa) of component A at a given temperature is equal to the vapor pressure of pure A multiplied by the mole fraction of A (XA) in solution is known as Answer: Raoult's Question: Q49 Identify the type of condenser used for cooling evaporating solvents Answer: Lie-big condenser Question: Q50 Which of the following does not have effect on distillation process? Answer: Concentration Question: Q51 At any given temperature a liquid is in equilibrium with its vapour Answer: true Question: Q52 A common aplication of distillation process is Answer: Sieving Question: Q53 Electronic balance is primariy used for Answer: Measuring weights Question: Q54 Which of the following apparatus can not be used in distillation? Answer: Graduated cylinder Question: Q55 Distillation is used to separate the mixture of Answer: Miscible liquid Question: Q56 Extremely corrosive substances like hydrofluoric acid are handled in Answer: Polyethylene containers Question: Q57 To avoid making error during weighing one is advised to use Answer: One balance only Question: Q58 The vessel to be weighed should be placed Answer: In the centre Question: Q59 If a procedure tells you to �??Add about 3 g of ammonium sulphate�?� which balance would you use? Answer: Top loading Question: Q60 In order to zero weighing baance before taking measurement one has to Answer: Tare Question: Q61 A symbol of skull with crossed bones is indicating Answer: Corrosive Question: Q62 Simple eating and drining can be allowed in the laboratory Answer: False Question: Q63 Carcinogenic substances are capabe of causing Answer: Cancer Question: Q64 Substances having low boiling points are very volatile and Answer: Flammable Question: Q65 Substance is called deliquescent because it Answer: Absorbs moisture and disslove in it Question: Q66 It is aways advised to use water in putting off laboratory fires Answer: False Question: Q67 Chemical subtances capable of eating away body tissues are Answer: Corrosive Question: Q68 Fire extinguishers are normally aimed at Answer: Base of the flame Question: Q69 Flammable solvents are advised to be handled with caution to avoid Answer: Fire Question: Q70 First aid to inhalation of toxic substancea should be Answer: Taking out to to fresh air Question: Q71 A person suffering from cuts is advised to be treated by Answer: Pressure on the area Question: Q72 Mishandling glasswares can lead to breakage and the risk of Answer: All of them Question: Q73 Chemical burns can also be treated by washing with excess Answer: Water Question: Q74 If a chemical does get into your eye, flush it with gently Answer: Water Question: Q75 It is recommended to work alone in the aboratory Answer: false Question: Q76 Long term exposure to benzene can lead to Answer: Cancer Question: Q77 When mixing acid and base, it is always recommended to Answer: Pour acid into water Question: Q78 If cloth is on fire and there is no shower one is recommended to Answer: Lay down and roll over Question: Q79 Safety glassess are recommended in order tp protect Answer: The eyes Question: Q80 Smoking is prohibited in the aboratory in order to prevent Answer: Fire accident
Comments