Calculations volumetric

The weight of X titrated in any volumetric analysis is given by the volume of titrant used multiplied by the weight of X titrated by 1 ml. 

One millilitre of titrant contains C/lOOOmol of titrant, where C is its concentration in mol/1, and reacts with C/lOOONmol of X, where N is the number of mol of titrant consumed by 1 mol of X. 

All volumetric calculations make use of this equation. If any five of the six parameters are known, the sixth can be found by simple rearrangement. For example, the amount of sample required to give a reasonablesized titration with a titrant of any given concentration is found by interchanging % X and W. 

In analyses where a measured excess of titrant is added and back- 

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Trimmell, M. L., 1987, Installation of Hydrocarbon Detection Wells and Volumetric Calculations within a Confined Aquifer In Proceedings of the National Water Well Association of Ground Water Scientists and Engineers and the American Petroleum Institute Conference on Petroleum Hydrocarbons and Organic Chemicals in Ground Water Prevention, Detection and Restoration, November, pp. 255-269. 

Test yourself on gravimetric and volumetric calculations at www.brightredbooks.net... 

From volumetric calculations and the distribution of hydrocarbons, it is conjectured that hydrocarbons in the Heidrun Field were derived, in the main, as overspill from the Smprbukk Field to the southwest. Recent exploration efforts have focused on the areas around the Heidrun unit area, particularly to the north, following expected migration pathways, and resulted in the discovery of Heidrun North (well 6507/8-4 Fig. 2). The next two wells in the northern part of the area met with less success, however. Well 6507/7-10 encountered shows and the 6507/8-6 well was dry. These results indicate that the hydrocarbon migration pathways are complex and that further work was required to more fully understand them. 

A moment s thought will confirm that the correct answer has been achieved. The only calculation error that could be made in this simple example is to get the factor upside-down (a so called inverted factor ). But, in the reaction, 25 mL of a f = 1.000 solution of Na2COs was neutralised by less than 25 mL of the acid. The acid must clearly be stronger than f = 1.000 if it required only 24.60 mL to neutralise the 25 mL of sodium carbonate. A check of this type should be carried out after every volumetric calculation. It is quick and easy to do and, to paraphrase the great Robert Burns, It wad frae monie a blunder free us, An foolish notion . 

Throughout this text, we base volumetric calculations exclusively on molarity and molar masses. We have also included in Appendix 6 a discussion of how volumetric calculations are performed ba.sed on normality and equivalent weights because you may encounter these terms and their uses in the industrial and health science literature. 

Most volumetric calculations are based on two pairs of simple equations that are derived from definitions of the millimole, the mole, and the molar concentration. For the chemical species A, we may write... 

In this section, we describe two types of volumetric calculations. The first involves computing the molarity of solutions that have been standardized against either a primary-standard or another standard solution. The second involves calculating the amount of analyte in a sample from titration data. Both types are based on three algebraic relationships. Two of these are Equations 13-1 and 13-3, both of which are based on millimoles and milliliters. The third relationship is the stoichiometric ratio of the number of millimoles of the analyte to the number of millimoles of titrant. 

In determining the number of significant figures to retain in volumetric calculations, the stoichiometric ratio is assumed to be known exactly without uncertainty. 

Volumetric Calculations Using Normality and Equivalent Weight... 

As a consequence, stoichiometric ratios such as those described in Section 13C-3 (page 343) need not be derived every time a volumetric calculation is performed. Instead, the stoichiometry is taken into account by how the equivalent or milliequivalent weight is defined. 

Appendix 4 Formation Constants at 25°C A-10 Appendix 5 Standard and Formal Electrode Potentials A-12 Appendix 6 Use of Exponential Numbers and Logarithms A-15 Appendix 7 Volumetric Calculations Using Normality and Equivalent Weight A-19... 

VolCall Types of Reactions - Acid/Base - Precipitation - Redox. Given Stoichiometry - Volumetric Calculations - Molarity/Volume/ Weight. 

VolCal2 Limiting Reactions - Calculation of Stoichiometry Factors - Working Method - Volumetric Calculations. 

Chapter 1, Moles and Molarity , includes a discussion of volumetric calculations, based on supplied stoichiometry factors for equations, including limiting reagents. It is included as a first chapter to get students without any previous knowledge of chemistry started on a practical course for volumetric chemistry that usually accompanies an introductory inorganic lecture course. 

Chapter 4 describes how the Chemical Properties of the Elements are related to their valence shell configuration, i.e. characteristic or group oxidation number, variable valence, ionic and covalent bonding. This chapter includes a section on the volumetric calculations used in an introductory inorganic practical course, including the calculation of the stoichiometry factors for chemical reactions. 

Chemists express solution concentrations in a number of ways. Some are more useful than others in quantitative calculations. We will review here the common concentration units that chemists use. Their use in quantitative volumetric calculations is treated in more detail below. 

We shall use molarity throughout the majority of the text for volumetric calculations. However, another useful concentration unit for volumetric calculations is normality, which uses the concepts of equivalents and equivalent weights in place of moles and formula weights. Normal concentration depends on the particular reaction, and the reaction should be specified. Some instructors prefer to introduce the concept of normality, and students are likely to encounter it in reference bop. Therefore, a review of equivalents and normality is given following the discussion of calculations using molarity. 

Learn these relationships well. They are the basis of all volumetric calculations, solution preparation, and... 

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