Wzorowane na: Chemistry SL Paper 1B, November 2025, TZ1, pytanie 2(d). Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Informacja do zadań 2a-2d.
A student was given a small block of an unknown metal and used calorimetry to identify it. The block, of mass 3.35 g, was kept in beaker A, which contained water held at 90.00 °C, until it had reached the temperature of the water. It was then transferred quickly into beaker B, which contained 6.25 g of water at 21.45 °C. The highest temperature reached by the water and the metal together in beaker B was 24.65 °C.
| Quantity | Value |
|---|
| Mass of the metal block / g | 3.35 |
| Temperature of the metal in beaker A / °C | 90.00 |
| Mass of water in beaker B / g | 6.25 |
| Temperature of the water in beaker B before the metal was added / °C | 21.45 |
| Highest temperature of water and metal in beaker B / °C | 24.65 |
Deduce, from the results obtained, two sources of systematic error in this procedure.
Any two of:
heat lost from the metal «to the air» while it is being transferred from beaker A to beaker B ✔
heat lost from the water in beaker B to the surroundings «beaker not insulated/no lid» ✔
water evaporating from beaker B while the hot metal is added ✔
heat absorbed by beaker B itself «heat capacity of the beaker not included in the calculation» ✔
[2 max], one mark per source. The measured value is below the accepted value for zinc, so accept only errors that make the temperature rise of the water smaller than it should be. Accept 'the mass of water is very small' and 'tap water rather than distilled water was used'. Do not accept 'heat loss' on its own, 'the metal may have oxidized', or 'hot water carried over on the metal' (that would raise the result). Do not penalize failing to name the beaker more than once.
Every accepted error explains the direction of the discrepancy: the water gained less heat than the metal lost, so the calculated value comes out too low.
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Policz na kartce jak na maturze, odsłoń klucz i porównaj. Potem odhacz, żeby wiedzieć, co masz już za sobą.
ZrobioneOdhaczanie zapisuje się na Twoim koncie, więc wymaga darmowego konta. Zajmuje chwilę i wracasz do tego samego zadania.