VEGYÉSZ ISMERETEK ANGOL NYELVEN

Size: px

Start display at page:

Download "VEGYÉSZ ISMERETEK ANGOL NYELVEN"

Ernest Hamilton
6 years ago
Views:

1 ÉRETTSÉGI VIZSGA május 17. VEGYÉSZ ISMERETEK ANGOL NYELVEN KÖZÉPSZINTŰ ÍRÁSBELI VIZSGA május 17. 8:00 Időtartam: 180 perc Pótlapok száma Tisztázati Piszkozati EMBERI ERŐFORRÁSOK MINISZTÉRIUMA Vegyész ismeretek angol nyelven írásbeli vizsga 1711

2 Important Information You may solve the questions in any order you like. In certain places, the subquestions may be solved even if the preceding sub-question has not been completed. You may use a non-programmable calculator to solve the questions, but no other aids are allowed. Read the introduction to questions carefully and comply with the instructions given. Write your solutions in blue or black pen. Any solutions or sections of solutions that have been crossed out will not be given any points. Maximum points are only awarded for calculation questions if the main steps of calculation are shown in the solution. Certain questions specify that points are deducted for wrong answers. Make sure you manage the time available well; write legibly and attempt to convey your thoughts clearly and coherently. If possible, solve the questions in the space provided for this purpose. You may request additional pages if needed, but make sure you mark which question you are solving on the sheet. Write your name on additional sheet as well. Good luck with your examination! 1711 írásbeli vizsga 2 / május 17.

3 Question 1 Please read the description of the synthesis of barium carbonate. Reaction: BaCl2 2 H2O + Na2CO3 10 H2O = BaCO3 + 2 NaCl + 12 H2O 16 points total Using a lever-balance, measure out 12.2 g of crystalline barium chloride (BaCl2 2 H2O). Using a lever-balance, measure out an amount of hydrated sodium carbonate (Na2CO3 10 H2O) that is 10 percent more than the amount required by the stoichiometric relationship. Dissolve both substances separately in about 100 to 150 cm 3 of water each. Warm up the solutions to about C, then mix them together. Place the solution in a water bath and keep it warm for about 2 3 hours. Decant and filter the solution. Wash the precipitate until the filtrate stops producing precipitate when mixed with silver nitrate dissolved in dilute nitric acid. Dry the crystals obtained in an oven at 105 C until constant weight. Molar masses: BaCl2: g/mol Na2CO3: g/mol BaCO3: g/mol H2O: 18.0 g/mol A) Calculate the amount of hydrated sodium carbonate to be measured out. B) Calculate the yield (mass) of barium carbonate that can be produced theoretically using the above amounts of reagents. C) Calculate the yield, if the mass of the actually produced dry crystals is 8.37 g írásbeli vizsga 3 / május 17.

4 D) When BaCO3 is heated together with sulfur, the following reaction takes place: 4 BaCO3 + 4 S = 3 BaS + BaSO4 + 4 CO2 Calculate the volume of carbon dioxide (at 25 C and standard pressure) that is generated, when the amount of BaCO3 product actually produced is heated together with sulfur. E) Concerning the test using silver nitrate dissolved in dilute nitric acid: The aim of the test:... The colour of precipitate (if any):... The chemical equation of precipitate production:... F) Why should the solution be kept warm?... G) Please underline in the list below the names of equipment/devices that are certainly NOT required for the experiment described above. Attention: Incorrect underlining will be sanctioned by loss of points. analytical balance burette reflux cooler baker gas burner round-bottom flask lever-balance test tube tube rack ceramic heating mesh watch-glass drying oven filter paper glass rod tripod reagent spoon water bath Question 2 10 points total 2.0 dm 3 of hydrochloric acid measuring solution with a concentration of 0.25 mol/dm 3 should be prepared. The concentration of the available hydrochloric acid is 37% (according to its label), and the weight of one litre is 1185 g. A) Calculate the theoretical amount (in cm 3 ) of the concentrated solution that should be added írásbeli vizsga 4 / május 17.

5 B) How much solution must be used in practice, as compared to the theoretically calculated value? Please explain your answer briefly C) The exact concentration of the prepared solution was determined by titration using KHCO g of KHCO3 was titrated using the measuring solution and methyl orange indicator cm 3 of the measuring solution was used up. Write down the chemical equation of the titrating reaction, and calculate the exact concentration of the measuring solution. According to the Analytical Pocketbook the molar mass of KHCO3 is g/mol. M(HCl) = 36.5 g/mol 1711 írásbeli vizsga 5 / május 17.

6 Question 3 7 points total Classify the aqueous solutions of the substances below according to electrolyte strength. Put an X mark in the appropriate cell. There must be only one X mark in each row. Question 4 Substance Acetic acid Sodium sulphate Dissociation constant mol/dm 3 Phosphoric acid K1 = 1, Sulphurous acid K1 = 1, Carbonic acid Trichloro-acetic acid K = 1, Ammonia Strong Medium strength electrolyte Weak 6 points total Pair the indicators listed in the last column with the volumetric titrations listed in the first two columns. Write the number of the indicator in the appropriate cell in the column labelled 'Num'. Measuring solution A) NaOH CH3COOH B) NaOH HCl C) EDTA Ca 2+ D) KMnO4 Oxalic acid E) AgNO3 NaCl F) NaOH H2SO4 Substance to titrate Num Indicator 1 phenolphtalein 2 fluorescein 3 starch 4 murexide 5 no indicator 6 methyl red 7 methyl orange 1711 írásbeli vizsga 6 / május 17.

7 Question 5 15 points total The following table lists the amounts of various anhydrous substances (in units of grams) that can be dissolved in 100 g of water at different temperatures: Substance Water of hydration 0 C 20 C 50 C 80 C 100 C AlCl3 6 H2O CuCl2 2 H2O CuSO4 5 H2O KBr KNO MgBr2 6 H2O NH4Cl NaNO A) Select the substance whose solubility shows the highest degree of dependence on temperature, and draw its solubility versus temperature graph. Substance selected:... B) Using data in the table, calculate how many grams of sodium nitrate and how many cm 3 of water are required to prepare 300 g of a solution that is saturated at 80 C. The density of water should be taken as 1.00 g/cm írásbeli vizsga 7 / május 17.

8 C) Using data in the table, calculate how many grams of hydrated MgBr2 are precipitated, when 200 g of a solution that is saturated at 50 C is cooled to 0 C. M(MgBr2) = g/mol M(H2O) = 18.0 g/mol Question 6 15 points total From the list below, select five pairs of substances whose reactions satisfy the conditions listed in the cells of the table. Write down the corresponding chemical equations and state the names of the reaction products. Substances: methyl alcohol, NaOH, Cl2, ethene; benzene, acetic acid, acetaldehyde, H2; phenol A) Ester production: Name of product: B) Acid-base reaction: Name of product: C) Reduction: Name of product: D) Addition: Name of product: E) Substitution: Name of product: 1711 írásbeli vizsga 8 / május 17.

9 Question 7 6 points total List the names (or the relevant groups of compounds) of the active ingredients of the following inorganic and organic household chemicals: A) Laundry detergent:... B) Antifreeze liquid:... C) Representative component of natural gas:... D) Components of gas in household pressure bottles:... E) Disinfectants and bleaching agents:... F) Descaler (scale remover):... Question 8 Complete the drawing of the standard atmospheric distillation apparatus on the right. Add any component(s) required if heating is to be done by an air-bath. You should also indicate the direction of the flow of cooling water. Name the numbered components of the distillation apparatus. 1:... 2:... 3:... 4:... Question points total 4 8 points total In a laboratory there is 10.0 dm 3 of sulphuric acid with a ph of 2.50 that is not needed any more. We want to neutralize it before we pour it down the sink. Neutralisation should be done by using the available NaOH solution with a ph of A) Calculate the concentration (mol/dm 3 ) of the sulphuric acid solution. B) Calculate the concentration of the NaOH solution. C) Calculate the volume of NaOH solution required for the neutralisation of the above mentioned sulphuric acid solution írásbeli vizsga 9 / május 17.

10 Question 10 8 points total A) In order to perform a permanganometric analysis, we have to determine the exact concentration of the KMnO4 measuring solution. We measure out g sodium oxalate, and find that 20.5 cm 3 measuring solution is required for its titration. The chemical reaction of titration is the following: 2 KMnO Na 2 C 2 O H 2 SO 4 = 2 MnSO 4 + K 2 SO Na 2 SO CO H 2 O Calculate the exact concentration of the KMnO4 measuring solution. M(Na2C2O4) = g/mol B) We immersed a sheet of iron into a dilute solution of sulphuric acid. After a while we removed the iron sheet and transferred the solution to a cm 3 measuring flask. We filled up the flask to the mark and homogenised the solution by mixing. We took out 20.0 cm 3 portions of the solution from the flask with a pipette, and determined their iron contents by titration with the above mentioned KMnO4 measuring solution. In the parallel titrations, the following amounts of measuring solution were consumed: 18.8 cm 3, 18.4 cm 3, 18.5 cm 3, 18.5 cm 3. Calculate the amount of iron that was dissolved in the dilute sulphuric acid solution. The chemical reaction of the titration is the following: 10 FeSO4 + 2 KMnO4 + 8 H2SO4 = K2SO4 + 2 MnSO4 + 5 Fe2(SO4)3 + 8 H2O A(Fe) = g/mol 1711 írásbeli vizsga 10 / május 17.

11 1711 írásbeli vizsga 11 / május 17.

12 Question number Theoretical questions Calculation questions Total Points scored maximum points Total: Points scored in written examination: 100 Date Correcting teacher Feladatlap pontszáma egész számra kerekítve programba elért beírt dátum dátum javító tanár jegyző 1711 írásbeli vizsga 12 / május 17.

VEGYÉSZ ISMERETEK ANGOL NYELVEN KÖZÉPSZINTŰ ÍRÁSBELI VIZSGA JAVÍTÁSI-ÉRTÉKELÉSI ÚTMUTATÓ

1711 ÉRETTSÉGI VIZSGA 2017. május 17. VEGYÉSZ ISMERETEK ANGOL NYELVEN KÖZÉPSZINTŰ ÍRÁSBELI VIZSGA JAVÍTÁSI-ÉRTÉKELÉSI ÚTMUTATÓ EMBERI ERŐFORRÁSOK MINISZTÉRIUMA Guidelines for evaluating the performance