Zadanie 1c
Wzorowane na: Chemistry SL Paper 1B, May 2026, TZ2, pytanie 1(c). Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Informacja do zadań 1a-1h.
A student investigated how temperature affects the intensity and the duration of the light given out when alkaline luminol solution reacts with hydrogen peroxide in the presence of a catalyst, hexacyanoferrate(III) ions.
Four beakers, each holding 50.0 cm3 of the same alkaline luminol solution, were placed one at a time in a water bath inside a darkened box, the bath being at a different temperature for each run. In every run, 10.0 cm3 of hydrogen peroxide solution and one small crystal of the catalyst were added and the mixture was stirred once. A light sensor beside the beaker recorded the light intensity every 30 seconds for 60 minutes.
The results are shown on the graph. Each curve is labelled with the temperature of the water bath.
Polecenie
Discuss the range of the independent variable and the quantity of data in this investigation.
Sprawdź rozwiązanieUkryj rozwiązanieKlucz CKE i punktacja
Odpowiedź z klucza
Range:
the temperatures cover only about 35 °C «20.6 to 55.7 °C» and are unevenly spaced/there is no run below room temperature or above 56 °C ✔
OR
the 20.6 °C run was still above the baseline after 60 minutes, so it was not recorded for long enough ✔
Quantity:
only one run at each temperature, so repeats are needed «to calculate a mean and judge the spread» ✔
OR
only four temperatures, too few to show the shape of the relationship ✔
Schemat punktowania
M1: a valid comment on the range, using the temperatures or the time axis. M2: a valid comment on the quantity, referring to repeats or to the number of temperatures. 'Not enough data' on its own scores 0.