Sample CalculationsStandardized molarity of “0.01 M” NaOH solution, trial 10.063g of KHP @ 204.2g/mol 0.063/204.2 = 3.09E-4 mole KHP28mL of 0.01M NaOH added3.09E-4 moles KHP/0.028 L NaOH = 0.011019M NaOH Initial concentration of phosphoric acid in cola sample 10 mL @ 0.0115M (averaged) NaOH added = 0.000115 moles NaOHmoles NaOH / initial H3PO4= 0.000115/0.02 = 0.00575 M H3PO4Ka1 calculated non-graphically, from initial pH and [H3PO4]
DiscussionExperiment #20 dealt with two main sections. the objectives for these two sections were to standardize a sodium hydroxide solution via titration using a visual indicator, to conduct a pH titration of phosphoric acid in a cola drink with standardized base for the determination of the concentration of the phosphoric acid in a cola drink as well as the acid dissociation constants of phosphoric acid, and to determine the extent of ionization of phosphoric acids.
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pH, Sodium hydroxide, Phosphoric acid, Cola Drinks