SET A CLUSTER 1, 2, 3 Chemtech Reviewer PDF

SET A d. After turning on, allow the spectrophotometer CLUSTER 1 to initialize and stabilize according to its user manual. 1. The following will cause...

SET A d. After turning on, allow the spectrophotometer CLUSTER 1 to initialize and stabilize according to its user manual. 1. The following will cause drift errors in an ChTLE B.E 2019 A#55 analytical balance except: 7. In maintenance and storage of pH meters, which a. Balance door is open. of the following procedure shall not be done? b. Balance is not levelled. a. To keep the electrode bulb moist during c. Air currents are present in the laboratory. storage, store the electrode in distilled water. d. Temperature of the balance and the sample to b. Rinse pH electrodes in between measurements. be weighed is the same. c. Blot the electrode dry after rinsing the pH electrodes. 2. It is a document that provides useful d. Mild soap solution may be used in general information on the chemical hazards, advice on cleaning of the electrodes safe handling, use and storage, and the emergency measures to be followed in case of an accident. It 8. In using fume hoods, the following shall be usually contains 16 headings. done, except for: ChTLE B.E 2019 A#58 a. Certificate of Analysis a. Ensure the exhaust is operating before using the b. Product Specification hood. ChTLE B.E OCT2022 c. Safety Data Sheet b. The hood shall be kept closed, except during d. Environmental Compliance Certificate apparatus set-up or when working within the hood. 3. Type of chemical that can cause an allergic c. The hood may be used as a permanent storage reaction in the airways following inhalation of the area for volatile chemicals when an appropriate chemical. ChTLE B.E 2019 A#93 storage cabinet is not available. a. Oxidizer d. Items contaminated with odorous or hazardous b. Corrosive materials should be removed from the hood only c. Carcinogen after decontamination or if placed in a closed d. Respiratory Sensitizer outer container to avoid releasing contaminants into the laboratory air. 4. Ammonia solution can be stored with the following chemicals except for: 9. Which of the following does not require a a. acetic acid solution ChTLE B.E 2019 A#95 minimum of annual third-party calibration? b. sodium hydroxide solution a. analytical balance c. 2-propanol solution ChTLE B.E OCT2022 b. drying oven d. cyclohexane solution c. autoclave d. sets of weights 5. First consideration for chemical storage shall be based on its: 10. Which of the following is an oxidizing a. frequency of usage chemical? b. compatibility with other chemicals a. potassium dichromate c. size of the container b. sodium hydride d. alphabetical order c. magnesium d. sodium 6. In operating a UV-Vis spectrophotometer, the following shall be done, except for: 11. In starting-up laboratory operations the a. Before turning on the power, check if the following should be observed except ________. sample holder does not contain anything. a. Turning on the hoods, vents and exhaust fans. b. Keep the sample compartment open during b. Turning the equipment and instruments on. measurement. c. Performing the analysis immediately. c. If there are any spillage that gets onto the d. Monitoring operating parameters. instrument, immediately wipe it away. ChTLE B.E 2019 A#57 12. The following must be avoided in using the d. When removing the heated material, use analytical balance except ______________. polyethylene gloves to protect your hand from a. Weighing warm objects in the balance. heat. b. Closing the draft shield before reading the result. 18-20. The absorbance of different concentrations c. Placing the sample not at the center but on the of potassium permanganate determined through side of the pan. UV-Vis Spectrophotometer is shown below. d. Touching the samples or sample containers with your bare fingers. Concentration, ppm Average Absorbance 1.11 0.015 13. Which of the following must be performed 22.2 0.236 before using the analytical balance? 44.4 0.512 a. Cleaning the balance and removing sample 66.6 0.751 residues. 88.8 1.062 b. Determine the sensitivity of the balance using calibration weight. 18. Calculate for the equation of the line. c. Checking the level of the balance by adjusting a. y = 0.0119x – 0.0147 the air bubble. b. y = 0.0119x + 0.0147 d. All of the above. c. y = 0.0147x – 0.0119 d. y = 0.0147x + 0.0119 14. Sealable enclosures containing desiccants used to protect chemicals 19. Calculate for the linearity of the calibration which are hygroscopic, or which react with water curve. from humidity. a. r2 = 0.989 a. Mortar and Pestle b. r2 = 0.998 b. Desiccator c. r2 = 0.0119 c. Evaporating dish d. r2 = 1.012 d. Separatory Funnel 20. The Quality Control Sample for this run gave an 15. To determine the specific gravity of a liquid, average absorbance reading of 0.486. The which of the following glass wares should be used? theoretical concentration of the QC sample is 44.4 a. volumetric flask ppm. Calculate for the % error of this QC run. b. pycnometer a. 5.24% c. pipette b. 5.52% d. graduated cylinder c. 4.65% d. 0.052% 16. Preparation of highly toxic and volatile compounds should be carried out in an efficient CLUSTER 2 ________. 1. How many grams of sodium chloride are a. canopy hood required to prepare 250 mL of a solution of 1 M b. laminar hood sodium chloride? c. fume hood a. 7.3054 grams d. any of the above b. 14.6108 grams c. 29.2216 grams 17. Which of the following shall not be followed d. 43.8324 grams when boiling a solution in a hot plate? a. Make sure that the glass ware being used is heat 2. Determine the volume of the following: resistant b. Inspect the glass ware for cracks before putting it in the hot plate. c. Add boiling stones to facilitate boiling.  11. Method of passing the sample through a metal or plastic mesh of a uniform cross-sectional area to separate particles into uniform sizes. a. sieving b. pulverizing c. macerating d. milling a. 24 mL and 75 mL b. 25 mL and 75 mL 12. Method that involves mechanical cutting of c. 24 mL and 74 mL sample into smaller parts d. 25 mL and 73 mL a. sieving b. chopping 3. In recording laboratory results, the following c. crushing shall be done, except: d. blending a. Use permanent ink b. When an error is committed, put multiple lines to cross out the wrong data 13. This refers to a single sample or measurement c. Always indicate the date of analysis taken at a specific time or over as short a period as d. Record all necessary details including qualitative feasible. observations a. grab sample b. composite sample c. laboratory sample 4. In determination of chlorides using d. none of the above argentometric titration, what indicator shall be used? 14. A sample comprising two or more increments selected to represent the material being analyzed. a. phenolphthalein a. grab sample b. ferroin b. composite sample c. methyl red c. laboratory sample d. potassium chromate d. none of the above 5. In sample acceptance, which of the following 15. Which of the following parameters shall be shall be checked? analysed immediately after collection? a. sample density a. Density b. sample integrity b. Temperature c. amount of sample c. Viscosity d. both b and c d. Solids 6-10. Choose the letter that corresponds to the 16. Method by which the sample is processed to correct color change that occurs for each be uniform in texture and consistency by breaking indicator. down into smaller parts and blending Indicator Color a. grinding Acid Base b. mincing Phenolphthalein 6. d. pink c. homogenizing colorless d. pressing Methyl Orange 7. c. yellow 8. a. red Bromcresol Green 9. b. blue 17. Type of subsampling in which the sample is yellow mixed to form a pile and then spread out to a Phenol Red 10. a. red flattened disk. The disk is then divided into 4 parts yellow and one of the opposite pair is used as the laboratory sample. a. red b. blue c. yellow d. pink a. coning and quartering b. grab sampling b. Waste treater c. splitters c. Waste transporter d. rotational traversing cut d. Pollution Control Officer 4. Wastes containing mercury and arsenic should 18. Sample preparation that involves the process be classified as what type of waste? of decomposition of organic matter a. Alkali waste a. ashing b. Wastes with inorganic chemicals b. homogenization c. Reactive chemical wastes c. fusion reaction d. Stabilized Waste d. liquid extraction 5. In handling acid wastes, what type of protective 19. The following are good sampling practices gloves should be used? ChTLE B.E 2019 A#86 except: ChTLE B.E 2019 A#65 a. Cloth gloves a. Take several increments and composite them to b. Surgical gloves form the sample. c. Rubber gloves b. If possible, mix the material before getting the d. Disposal plastic gloves sample. c. Collect the sample in a container made if 6. The following are the minimum requirements material that will chemically react with the for Hazardous Waste storage facilities except: sample. a. Accessible in cases of emergency and for d. Sample frequently enough to allow for the purposes of inspection and monitoring. identification of process cycles. b. Enclosed and should not be ventilated. c. Have floors that are impermeable to liquids and 20. Process of which the sample is heated to the resistant to attack by chemicals, not slippery, and boiling point of the solvent and volatile analytes constructed to retain spillages are concentrated in the vapour phase, condensed d. Be properly secured and not easily accessed by and collected. ChTLE B.E 2019 A#67 unauthorized persons. a. evaporation ChTLE B.E OCT2022 b. distillation 7. What type of container must be used for acid or c. liquid-liquid extraction alkali wastes? d. oven drying a. Polyethylene Drums b. Metal drums CLUSTER 3 c. Fiber Drums 1. What should be the pH of a waste for it to be d. Cloth container considered as an “acidic waste”? a. pH < 2 8. In cases of acid spills, which of the following can b. pH < 3 be applied to the spill before treating it with c. pH 4 adsorbent material? d. pH 7 a. Sodium bicarbonate b. Water 2. What should be the pH of a waste for it to be c. Acetic acid considered as an “alkali waste”? d. Sodium bisulfite a. pH 7 b. pH > 2 9. It is a hazardous waste characteristic which c. pH 10 applies to waste liquids with a flash point less than d. pH > 12.5 140°F or solids capable of spontaneous combustion under normal temperature and 3. This refers to a person who produces hazardous pressure. wastes, through any institutional, commercial, a. Ignitability industrial or trade activities. b. Reactivity a. Waste generator c. Corrosivity d. Toxicity contamination that can still be converted into suitable beneficial use. 10. It is a hazardous waste characteristic which a. Recyclable wastes applies to aqueous solutions with a pH less than or b. Residual wastes equal to 2 or greater than or equal to 12.5. c. Compostable wastes d. Special wastes a. Ignitability b. Reactivity 16. These waste materials refer to items designed c. Corrosivity to cut or puncture skin and sharp items with d. Toxicity human blood and body fluids or bacteria. a. Hazardous glass and plastics 11. It is a hazardous waste characteristic which b. Non-hazardous trash applies to materials that are normally unstable or c. Waste or surplus chemicals explosive. They can cause explosions, toxic fumes, d. Sharps gases or vapours when mixed with water. a. Ignitability 17. These are organic chemicals that are resistant b. Reactivity to environmental degradation through chemical, c. Corrosivity biological, and photolytic processes. d. Toxicity a. Persistent Organic Chemicals (POPs) b. Ozone’s 12. It is a hazardous waste characteristic which c. Carcinogen applies to wastes that have the potential to d. Mutagen contaminate groundwater if improperly disposed of. These materials are regulated as hazardous 18. This refers to any liquid that passes through a waste due to their potential to leach out specific landfill and has extracted dissolved and suspended toxic substances in a landfill. matter from it. a. Ignitability ChTLE B.E 2019 A#85 a. Filtrate b. Reactivity b. Aquifers c. Corrosivity c. Leachate d. Toxicity d. Groundwater 13. A solid waste management practice which 19. Which of the following practices must be refers to the controlled decomposition of organic avoided in handling liquid chemicals? matter by microorganisms, mainly bacteria and a. Wear goggles, face shield, rubber gloves, gum fungi, into a humus-like product. boots and aprons while handling against splashing. a. Composting b. Treat all liquids as dangerous, until you know b. Recycling that they are safe. c. Bioremediation c. Handle very carefully the bottles / containers d. Reducing which have no labels. d. Carry acid in an open container. 14. These are biodegradable wastes such as food waste, garden waste, animal waste and human 20. It is a general term denoting any wastewater, waste that can undergo biological degradation partially or completely treated, or in its natural under controlled conditions and can be turned state, flowing out of a manufacturing, industrial or into compost. treatment plant. a. Recyclable wastes a. Influent b. Residual wastes b. Effluent c. Compostable wastes c. Coastal water d. Special wastes d. Fresh water 15. These are any waste materials that can be TRUE OR FALSE – CLUSTER 1 retrieved from the waste stream and free from 21. The conductivity value of a liquid solution 23. What would be the colour change at the increases as the temperature decreases as a result endpoint? pink to colourless of higher ion mobility. false 24. Calculate the number of moles of sodium 22. The alkaline effect is the phenomenon where hydroxide solution used. 0.00625 mol NaOH H+ ions in the gel layer of the pH-sensitive membrane are partly or completely replaced by 25. Calculate the concentration of the alkali ions. true hydrochloric acid in mol/L. 0.2841 mol/L 23. In pH measurements, if the solution is acidic, the H+ ions diffuse out of the layer and a negative For numbers 26 to 30. charge is established on the outer side of the membrane. false A.) A 25.5125 M stock solution of potassium dichromate was diluted by transferring 10.0 mL of 24. Karl Fischer titrator is used to determine the stock solution into a 50 mL volumetric flask viscosity of liquids. false and was diluted to mark with distilled water. This 25. For pipettes marked with To Deliver (TD), a solution is labelled as Solution 1. B.) 15.00 mL of small amount of liquid remaining on the tip should Solution 1 was transferred to a 25 mL volumetric not be blown out. true flask and was diluted to mark with distilled water. This solution is labelled as Solution 2. C.) 10.00 mL 26. Cuvettes must be cleaned in an ultrasonic of Solution 2 was transferred to a 50 mL cleaning bath. false volumetric flask and was diluted to mark with distilled water. This solution is labelled as Solution 27. In operating the centrifuge, opposing tubes 3. D.) 5.00 mL of Solution 3 was transferred to a 25 must be of equal weight. true mL volumetric flask and was diluted to mark with 28. To ensure that glass wares are thoroughly distilled water. This solution is labelled as Solution cleaned, the film of water which adheres to the 4. E.) 5.00 mL of Solution 4 was transferred to a 50 inner glass wall of the glass ware as it is emptied mL volumetric flask and was diluted to mark with must not be uniform. false distilled water. This solution is labelled as Solution 5. 29. Class B volumetric glass ware provides the highest accuracy and passes the ASTM standard 26. Calculate the concentration of potassium specification for laboratory volumetric glass ware. dichromate in Solution 1. Express the result in two false significant figures. 5.1 mol/L 30. In calibration of burettes, volume reading shall be taken with the eye higher than the liquid level 27. Calculate the concentration of potassium to avoid parallax error. False dichromate in Solution 2. Express the result in two significant figures. 3.1 mol/L PROBLEM SOLVING – CLUSTER 2 For numbers 21 to 25 28. Calculate the concentration of potassium dichromate in Solution 3. Express the result in two A solution of sodium hydroxide contained 0.250 significant figures. 0.61 mol/L mol/L. Using phenolphthalein indicator, titration of 25.0 mL of this solution required 22.0 mL of a 29. Calculate the concentration of potassium hydrochloric acid solution for complete dichromate in Solution 4. Express the result in two neutralisation. significant figures. 0.12 mol/L 21. Write the equation for the titration reaction. 30. Calculate the concentration of potassium 𝑵𝒂𝑶𝑯𝒂𝒒 + 𝑯𝑪𝒍𝒂𝒒 ↔ 𝑵𝒂𝑪𝒍𝒂𝒒 + 𝑯𝟐 𝑶 (𝒍) dichromate in Solution 5. Express the result in two significant figures. 1.2 x 10-2 mol/L 22. What laboratory glassware would you use to measure out (a) the sodium hydroxide solution? TRUE OR FALSE – CLUSTER 3 (b) the hydrochloric acid solution? a. pipette b. burette 21. Store concentrated acids and bases separately in enclosures made of corrosion-resistant materials. true 22. Keep fire extinguishers away from locations where chemicals are stored or used. false 23. Wastes containing live microorganisms can be treated by autoclaving or chemical disinfection. true 24. Purchasing of mercury-containing instruments must be avoided. true 25. Broken laboratory glassware’s can be disposed directly in trash cans or garbage bins. false