Zadanie 1a
Calculate the mass of solid potassium hydroxide that has to be weighed out.
Chemistry HL Paper 1B, November 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 17 zadań z tego arkusza, razem 35 punktów, każde z kluczem i schematem punktowania. Najwięcej zadań sprawdza: Experimental techniques and apparatus (6), Chromatography and Rf values (6), Molar concentration of solutions (5).
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Dodaj cały arkusz do zestawuZadanie 1b
Describe how the student should prepare this standard solution from the weighed solid using a 250.0 cm3 volumetric flask.
Zadanie 1c
The student pipetted 25.00 cm3 of the potassium hydroxide solution into a conical flask and titrated it with nitric acid, HNO3(aq), of concentration 0.1250 mol dm−3. The burette readings before and after the titration are…
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Zadanie 1d
Using the concentration determined in 1c and the intended concentration of 0.1500 mol dm−3, calculate the percentage error in the concentration of the potassium hydroxide solution. If you have no value from 1c, take the concentration to be…
Zadanie 1e
Explain why the potassium hydroxide solution has to be standardized before it is used in the titration. Assume that there are no systematic errors in the procedure.
Zadanie 1f
The student then used the potassium hydroxide solution standardized in 1c to titrate ethanoic acid, CH3COOH, whose concentration was not known. (i) Neutralizing 25.00 cm3 of the acid required 40.00 cm3 of the standardized…
Zadanie 2a
Using sections 1 and 2 of the data booklet, determine the amount of heat that the water in beaker B gained from the metal.
Zadanie 2b
Assume that the heat released by the metal is equal to the heat absorbed by the water in beaker B, calculated in 2a. Determine the specific heat capacity of the metal. Use section 1 of the data booklet. If you have no answer to 2a, take the heat transferred to…
Zadanie 2c
Using the table below, state the name of the metal from which the block is made.
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Zadanie 2d
Deduce, from the results obtained, two sources of systematic error in this procedure.
Zadanie 2e
State one other physical property that could be measured to identify the metal while leaving the block intact.
Zadanie 3a
Each beaker used as a chromatography chamber was covered with a watch glass while the solvent rose up the paper. Explain why the chamber has to be covered for the experiment to be properly designed.
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Zadanie 3b
Explain why the start line must be horizontal and must be above the level of the solvent when the strip is placed in the chamber.
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Zadanie 3c
For the orange dye, calculate the retardation factor, RF, obtained in each solvent system.
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Zadanie 3d
Deduce, giving a reason, which of the two dyes, orange or violet, is the more polar.
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Zadanie 3e
The student suspected that the ink contained more than four dyes, and that one of the spots was two dyes that had not separated. Suggest how the student could modify the chromatography experiment to test this idea.
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Zadanie 3f
Explain how the dyes are separated from one another in paper chromatography.
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