LabManuel1 - CHE 303 8/24/11 Introduction to Meaningful...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
CHE 303 8/24/11 Introduction to Meaningful Measurements: Standardization of HCl and the Determination of Sodium Carbonate. Educational Learning Objectives: 1. To further develop quantitative skills in order to obtain precise results. 2. To learn how to recognize and minimize sources of error in quantitative measurements. 3. To use error analysis to evaluate the quality of one’s data. In a titrimetric analysis a standardized solution, whose concentration is known, is used to determine quantitatively to within 2-3 ppt (part per thousand) the amount of an analyte present in a sample. The titrant is standardized prior to the determination, by titrating it against a known amount of primary standard. Primary standards are substances that have the following characteristics: 1. They can be obtained in high purity (impurities should not exceed 0.01 – 0.02%). 2. They are stable. It should be easily dried and not be hygroscopic. 3. They have a high equivalent weight (reduces the relative error in moles or equivalents due to weighing the sample). 4. They are readily available and of reasonable cost. For the standardization of HCl, we will use sodium carbonate as a primary standard. It can be easily dried, it is readily available, inexpensive, and stable. It has a reasonable molecular weight of 105.989 g/mol. Given the weight of the primary standard and the titrant volume required to reach the equivalence point, the molarity or normality of the titrant can be determined to four significant figures. Sodium carbonate reacts with hydrochloric acid in two steps:
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/04/2011 for the course CHE 303 taught by Professor Staff during the Fall '08 term at SUNY Stony Brook.

Page1 / 3

LabManuel1 - CHE 303 8/24/11 Introduction to Meaningful...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online