Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Based upon the molarities of the standardized HCl and standardized NaOH, and the

ID: 1050419 • Letter: B

Question

Based upon the molarities of the standardized HCl and standardized NaOH, and the volumes of each added to analyze the antacid samples, calculate the MILLIMOLES of HCl needed to neutralize the tablet per MILLIGRAM of sample. Use the same sequence as you entered the mass of the samples and report your results to 4 significant figures. Part IIC. Data Entry - No Scoring. For each of the three trials of the analysis of the antacid what was the volume of standardized NaOH required to titrate the residual standardized HCl after it reacted with the antacid? Enter the volumes in the same sequence as the corresponding mass of antacid sample and to the nearest 0.02 mL. e.g. 37.54 mL.

Explanation / Answer

Part IIc

Neutralization of antacid CaCO3

Entry#1

moles of antacid = 0.6060 g/100.087 g/mol = 6.055 mmol

moles of HCl needed = 2 x 6.055 mmol = 12.11 mmol

mmol of HCl/mg of tablet = 12.11/1.273 x 1000 = 9.513 x 10^-3 mmol/mg tablet

Entry#2

moles of antacid = 0.6020 g/100.087 g/mol = 6.015 mmol

moles of HCl needed = 2 x 6.015 mmol = 12.03 mmol

mmol of HCl/mg of tablet = 12.11/1.273 x 1000 = 9.45 x 10^-3 mmol/mg tablet

Entry#3

moles of antacid = 0.6000 g/100.087 g/mol = 5.995 mmol

moles of HCl needed = 2 x 5.995 mmol = 11.99 mmol

mmol of HCl/mg of tablet = 11.99/1.273 x 1000 = 9.42 x 10^-3 mmol/mg tablet