Buffer solutions are used to regulate pH . Write two equations to describe how a solution containing $$$\mathrm{HC}_{2} \mathrm{O}_{4}^{-}$$$ions acts as a buffer solution when small amounts of acid or alkali are added. ............................................................................................................................................... . .........................................................................................................................................

Chemistry

IGCSE&ALevel

CAIE

Exam No：9701_s24_qp_43 Year：2024 Question No：3(f)

Answer:

24.2.1.1 standard electrode (reduction) potential

24.2.1.2 standard cell potential

24.2.10 understand and use the equation

24.2.2 describe the standard hydrogen electrode

24.2.3.1 metals or non-metals in contact with their ions in aqueous solution

24.2.3.2 ions of the same element in different oxidation states

24.2.4 calculate a standard cell potential by combining two standard electrode potentials

24.2.5.1 deduce the polarity of each electrode and hence explain/deduce the direction of electron flow in the external circuit of a simple cell

24.2.5.2 predict the feasibility of a reaction

24.2.6 deduce from values the relative reactivity of elements, compounds and ions as oxidising agents or as reducing agents

24.2.7 construct redox equations using the relevant half-equations

24.2.8 predict qualitatively how the value of an electrode potential, E, varies with the concentrations of the aqueous ions