VEGYÉSZ ISMERETEK ANGOL NYELVEN KÖZÉPSZINTŰ ÍRÁSBELI VIZSGA JAVÍTÁSI-ÉRTÉKELÉSI ÚTMUTATÓ

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1 1711 ÉRETTSÉGI VIZSGA május 17. VEGYÉSZ ISMERETEK ANGOL NYELVEN KÖZÉPSZINTŰ ÍRÁSBELI VIZSGA JAVÍTÁSI-ÉRTÉKELÉSI ÚTMUTATÓ EMBERI ERŐFORRÁSOK MINISZTÉRIUMA

2 Guidelines for evaluating the performance of examinees (for correcting teachers) The correction and evaluation of written examinations must be performed on the basis of the evaluation guide. Evaluation of theoretical questions The questions may only be evaluated as per the partial points system specified in the evaluation guide. The indicated points can only be broken down further if specifically indicated. Resulting points may only be whole numbers. Answers provided in the correction-evaluation guide can only be awarded the points indicated. Evaluation of calculation questions No points may be deducted for the absence of partial results that were not specified as required (but are shown in the evaluation guide), provided the solution is correct and free from errors. (These partial results merely help the awarding of points for partial solutions.) Points may only be deducted for the absence of formulas and chemical equations used for the calculations if these were specifically required to be shown by the given question. Deductions that are different from those in the evaluation guide, but are nonetheless correct, can be awarded maximum points, and should also be awarded the partial points due as per the nodes specified. No points should be deducted for slight deviations in partial and final results arising from rounding. In the case of questions made up of multiple sub-questions, provided the final solution is not contradictory, the points due for a given sub-question may be awarded even if the examinee has used incorrect results they have arrived at an earlier subquestion to continue calculations. For calculation questions, sections that are professionally sound and clear, but which may be interpreted without detailed elaboration, should also be given maximum points. Evaluation of written (long-answer) questions In the case of written (long-answer) questions, solutions with different wording, but which are nonetheless professionally correct must also be accepted írásbeli vizsga 2 / május 17.

3 Question 1 16 points total A) 12.2 n(na2co 10 H2O) = n(bacl2 2 H2O) = = mol m(na2co 10 H2O) = ( ) = g The amount to measure out (including the excess) is: = 15.7 g Na 2 CO 10 H 2 O B) n(baco) = n(bacl2 2 H2O) = mol m(baco) = = 9.85 g C) 8.7 Yield: 100 = 85.0% 9.85 D) 8.7 n(co2) = n(baco) = = mol 197. V(CO2) = = 1.04 dm E) The aim of the test: To check if washing was sufficient (absence of chloride ions). Colour of precipitate (if any): white Chemical equation of precipitate formation: Cl + AgNO = AgCl + NO F) Why keep the solution warm: The particle size of the precipitate formed will be larger, so it will be easier to filter out. G) analytical balance, burette, reflux cooler, round-bottom flask For each correct underline add. Total: 4 points For each erroneous underline, subtract, in case of 4 or more erroneous underlines no points should be awarded. Question 2 10 points total A) n(hcl) = = 0.5 mol m(hcl) = = g m(7% HCl) = = 49. g V(7% HCl) = = 41.6 cm B) About 5 to 10% more. Explanation: Hydrochloric acid is volatile, the HCl content of the bottle is usually lower than what is indicated on the label. C) KHCO + HCl = KCl + CO2 + H2O n(khco) = = mol n(hcl) = n(khco) = mol c(hcl) = = mol/dm írásbeli vizsga / május 17.

4 Question Acetic acid Substance Sodium sulphate Dissociation constant mol/dm Strong Phosphoric acid K1 = Sulphurous acid K1 = Carbonic acid Trichloro-acetic acid K = Ammonia Each correctly placed mark should be awarded one point. Total: Question 4 A/1 B/7 C/4 D/5 E/2 F/6 Each correct answer should be awarded one point. Total: Question 5 A) 7 points total Medium Weak strength electrolyte 7 points 6 points total 6 points 15 points total Solubility, g/100g water Temperature, C Substance to select: KNO. The following aspects may be evaluated even if the selection of substance was incorrect: Assignment of captions and numbers to axis: one point each. Total: 2 points Correct placement of data points: 2 points Drawing the solubility graph: 1711 írásbeli vizsga 4 / május 17.

5 B) 100 g water g NaNO = 248 g solution for 248 g solution we need 148 g of NaNO for 00 g solution we need x g NaNO x = = 179 g NaNO 248 Amount of water needed: 00 g solution 179 g salt = 121 g = 121 cm C) Hydrated salt contains 100 = 6.0% MgBr Saturated solution at 50 C contains 100 = 51.0% MgBr Saturated solution at 0 C contains 100 = 47.6% MgBr2 191 Mass of solution: 200 g Mass of precipitated hydrated salt: m m (200 m) 47.6 = m = 200 = 44.2 g MgBr 2 6 H 2 O Question 6 15 points total A) Production of ester: CH OH + CHCOOH CHCOOCH + H2O Product: methyl acetate B) Acid-base reaction: C6H5OH + NaOH = C6H5ONa + H2O Product: sodium phenolate C) Reduction: CHCHO + H2 = CHCH2OH Product: ethanol D) Addition: C2H4 + Cl2 = Cl CH2 CH2 Cl Product: 1,2-dichloroethane E) Substitution: C6H6 + Cl2 = C6H5Cl + HCl Product: chlorobenzene Chemical equations should be awarded 2 points each; product names, each. Total: 15 points Other correct reactions are also acceptable. Correct names of any type (trivial, regular etc.) are acceptable. Question 7 6 points total A) Laundry detergent: soap, sulphonates B) Antifreeze liquid: glycol C) Representative component of natural gas: methane D) Components of gas in household pressure bottles: propane and butane E) Disinfectants and bleaching agents: sodium hypochlorite F) Descaler (scale remover): acetic acid, citric acid Each correctly filled row should be awarded (even if only a single example is given). Total: 6 points Other acceptable examples exist. Other chemical or commercial names are also acceptable írásbeli vizsga 5 / május 17.

6 Question points total 1: round-bottom flask (boiler) 2: clamp : thermometer 4: cooler Added elements: cooling water in- and outlet: iron tripod ceramic mesh inlet with air vent collector For some equipment alternative names are acceptable. Question 9 8 points total A) c(ho + ) = = mol/dm c(h2so4) = 0.2 c(ho + ) = = mol/dm B) poh = = 2.60 c(oh ) = = mol/dm c(naoh) = c(oh ) = mol/dm C) n(ho + ) = = mol n(naoh) = n(oh ) = n(ho + ) = mol n(naoh) V(NaOH) = = = 12.6 dm c(naoh) Question 10 8 points total A) Calculate the exact concentration of the KMnO4 measuring solution n(na2c2o4) = = mol n(kmno4) = n(na2c2o4) = = mol c(kmno4) = = mol/dm B) Solution consumed: cm n(kmno4) mol n(fe). 5 n(kmno4) mol 250 n(total Fe) mol 20 m(total Fe) g 1711 írásbeli vizsga 6 / május 17.

VEGYÉSZ ISMERETEK ANGOL NYELVEN KÖZÉPSZINTŰ ÍRÁSBELI VIZSGA JAVÍTÁSI-ÉRTÉKELÉSI ÚTMUTATÓ

angol nyelven középszint 1721 ÉRETTSÉGI VIZSGA 2018. május 16. VEGYÉSZ ISMERETEK ANGOL NYELVEN KÖZÉPSZINTŰ ÍRÁSBELI VIZSGA JAVÍTÁSI-ÉRTÉKELÉSI ÚTMUTATÓ EMBERI ERŐFORRÁSOK MINISZTÉRIUMA Guidelines for evaluating