Answer to Question #343970 in General Chemistry for Nina

Question

Double Indicator Titration

A groundwater sample was analyzed for its total alkalinity (assume that the alkaline constituents come from Na2CO3, NaHCO3 and NaOH, either alone or a permissible combination). For the analysis, a standardized 0.101M HCl solution was used.

Suppose a 30.0-ml sample required 13.2 ml of the titrant to reach phenolphthalein end point. Another 20.0 ml of the same water sample was titrated using methyl orange indicator and used 24.7 ml of the same titrant.

a. Determine the alkaline components of the sample

b. What are the molar concentrations of each component?

c. If the analyst did not boil the distilled water used to standardize the titrant in the problem, what will be the effect on the percentages of each component? Why?

Answer 1

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