Zadanie 2d
Wzorowane na: Chemistry SL Paper 2, May 2024, TZ2, pytanie 2(d). Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Polecenie
Atmospheric carbon dioxide and the pH of surface seawater were measured at a monitoring station over nineteen years. The graph shows the annual mean values.
(i) Outline the relationship between the carbon dioxide mixing ratio and the pH of the seawater.
(ii) Comment, based on the graph, on the conclusion that increasing atmospheric carbon dioxide is the cause of the fall in pH.
Sprawdź rozwiązanieUkryj rozwiązanieKlucz i punktacja
Odpowiedź z klucza
(i) a negative «inverse» correlation
OR
as the carbon dioxide mixing ratio rises, the pH falls ✔
(ii) any two of:
the data are consistent with the claim but cannot prove it
OR
a correlation does not show that one change causes the other ✔
a chemical link between the two must be given, e.g. CO2(g) + H2O(l) ⇌ H2CO3(aq) followed by ionization of H2CO3 to H+ ✔
other influences on the pH are possible, e.g. acid deposition, run-off, biological activity ✔
Schemat punktowania
(i) [1]: do not accept 'inversely proportional'. (ii) [2 max]: one mark per distinct point from the list.