Final answer:
The emf of a cell and ionization constant of an electrolyte are influenced by the ion concentrations at the anode and cathode. Cell potential, measured using a voltmeter, changes with ion concentration variations and standard conditions are applied to derive comparative potentials.
Step-by-step explanation:
The emf of a cell can be significantly affected by the concentration of electrolytes at the anode and cathode and by the ionization constant of the electrolyte. According to the Nernst equation, the cell potential varies with concentration changes of the reacting ions. In an electrochemical cell, the voltmeter measures the difference in potential (Ecell) which is impacted by the ion movements and concentration at the electrodes.
Using a pH meter, the ionization constant of an acid can be determined by measuring the potential difference that is dependent on the H+ concentration, where pH is related to [H+] by the equation pH = -log[H+]. Moreover, standard cell potentials (Eºcell) are measured under standard conditions to compare oxidation and reduction potentials of different substances, and corrections for nonideal behaviors are applied when necessary for more precise quantitative work.