Zadanie 4d
Wzorowane na: Chemistry HL Paper 2, May 2026, TZ1, pytanie 4(d). Treść, dane i kontekst są zmienione; sprawdzane umiejętności, format i punktacja jak w oryginale.
Darmowe konto pozwoli wrócić do niego później.
Informacja do zadań 4a-4d.
Sodium hydroxide, NaOH, can neutralize organic acids.
Polecenie
Suggest two different mixtures, each prepared from the unknown organic acid, that would produce a buffer solution.
Sprawdź rozwiązanieUkryj rozwiązanieKlucz CKE i punktacja
Odpowiedź z klucza
Mixture 1: the organic acid AND a salt of the acid «for example its sodium salt», giving a weak acid together with its conjugate base ✔
Mixture 2: an excess of the organic acid AND a smaller amount of base «for example NaOH(aq), less than the 20.0 cm3 needed per 25.0 cm3 of acid», so that the acid is partly neutralized and a mixture of the acid and its conjugate base is formed ✔
Schemat punktowania
[2] M1: weak acid (the organic acid) together with a salt of that acid; M2: partial neutralization of the acid by a base, leaving a mixture of the acid and its conjugate base. Accept a named base or a reactive metal for the formation of the salt in either mixture. Do not accept complete neutralization (equal amounts of acid and base) or 'acid and base' without an indication that the acid is in excess.