Zadanie 1a
Determine the mass of sodium thiosulfate pentahydrate, Na2S2O3 ⋅ 5 H2O, needed to prepare 250.0 cm3 of a 0.2000 mol dm−3 solution.
- Materiał graficzny
Chemistry SL Paper 1B, May 2025, TZ1
Zadania wzorowane na pytaniach z tego arkusza: te same umiejętności, format i punktacja, inne dane i kontekst. Treści arkusza IB nie publikujemy.
W bazie 13 zadań z tego arkusza, razem 25 punktów, każde z kluczem i schematem punktowania. Najwięcej zadań sprawdza: Molar concentration of solutions (7), Units, uncertainties and graphs (6), Experimental techniques and apparatus (4).
Rozwiąż arkuszCały arkusz po kolei. Wynik na końcu.
Dodaj cały arkusz do zestawuZadanie 1b
Explain how the 0.2000 mol dm−3 solution is prepared in a volumetric flask from the weighed solid.
- Materiał graficzny
Zadanie 1c
Suggest how to prepare 100.0 cm3 of a 0.05000 mol dm−3 sodium thiosulfate solution from the 0.2000 mol dm−3 solution.
- Materiał graficzny
Zadanie 1d
The student's results are shown below. Each time was measured to ± 0.1 s. Rather than diluting the stock solution, the student prepared every solution separately, weighing the required mass of the solid on a balance reading to ± 0.01 g and making each one up…
- Tabela do uzupełnienia
- Materiał graficzny
Zadanie 1e
State one safety concern arising from a product of this reaction, and a precaution that should be taken because of it.
- Materiał graficzny
Zadanie 2a
Suggest a sequence of experimental steps that would give a pure sample of each of the three components.
Zadanie 2b
The student recorded the following masses. Calculate the percentage by mass of iron and of calcium carbonate in the mixture.
- Tabela do uzupełnienia
Zadanie 2c
The three percentages in 2b add up to more than 100 %. Suggest an error that would explain this result and how it could be reduced or eliminated.
Zadanie 2d
The results did not support the student's hypothesis. Suggest what the student overlooked when forming the hypothesis.
Zadanie 3a
Draw a line of best fit on the graph, extrapolating it beyond the range of the data.
- Materiał graficzny
Zadanie 3b
State, in mathematical terms, how the absorbance of these solutions depends on their concentration.
- Materiał graficzny
Zadanie 3c
Deduce the equation that relates absorbance to concentration for these solutions, including the numerical value of the constant.
- Materiał graficzny
Zadanie 3d
Estimate the absorbance of a 0.400 mol dm−3 solution of nickel(II) sulfate.
- Materiał graficzny