Conversion of Concentration Of Solutions units

Introduction

Concentration is used to refer to the proportion of a solute in a solution. The study of the various units of concentration is a complex yet interesting topic. This chapter delves into the history, uses, and interesting facts surrounding the different units in the chemical solution studies.

History of Concentrations

The history of the numerous units of concentration goes as far back as Ancient Greece. The first example of a unit of concentration known has its roots in the studies of Hippocrates. He used parts per thousand in his studies. Subsequent centuries saw further theories on the measurement of concentration in different chemical solutions, which led to advances in the units of concentration.

Uses of Concentrations

The various units of concentration have numerous practical day to day uses. For example, mass concentration is used in calculations related to the mixture of two components such as gas and air. Volume percentages help to calculate the basis of an aqueous solution, for example, seawater. Molarity is used for intermediary calculations to determine equilibrium in a reaction, and weight fractions are utilized in oil-based products. Different units of concentration are utilized based on the specific use of the chemical solution.

Reference or Record Values

Reference or record values can be found in various sources ranging from journals to databases. As there are many different units of concentrations, each unit has its own set of reference point. Following is quick list of examples:

• 0.9% saline solution: This is a solution of sodium chloride (NaCl) in water that is commonly used in medicine and biology. It is called ""0.9%"" because it contains 0.9 grams of NaCl per 100 milliliters of water, which corresponds to a concentration of 9 grams per liter or 154 mM (millimoles per liter).
• 70% isopropyl alcohol (IPA) solution: This is a solution of IPA in water that is commonly used as a disinfectant and cleaning agent. It is called ""70%"" because it contains 70% (by volume) of IPA and 30% of water. This corresponds to a concentration of 35.3 grams per 100 milliliters or 470 mM.
• 1 Molar hydrochloric acid (HCl) solution: This is a solution of HCl in water that has a concentration of 1 mole per liter. This means that for every liter of solution, there is 1 mole (which is approximately 36.5 grams) of HCl dissolved in water.
• 0.1 N sulfuric acid (H2SO4) solution: This is a solution of H2SO4 in water that has a concentration of 0.1 normal (abbreviated as 0.1 N). Normality is a unit of concentration that is defined as the number of equivalents of a solute per liter of solution. In this case, the concentration of H2SO4 is 0.1 equivalent per liter, which corresponds to a concentration of 4.9 grams per liter.
• 5% glucose solution: This is a solution of glucose (C6H12O6) in water that has a concentration of 5% (by weight). This means that for every 100 grams of solution, there are 5 grams of glucose dissolved in water. This corresponds to a concentration of approximately 27.8 mM.

How to Convert

It is important to understand the basics of how to convert from one unit of concentration to another. In order for the user to utilize the multitude of units available, it is necessary to comprehend the conversion factors. For example, 1 Molar is equal to one mole per 1 liter. Likewise, 1ppm is equal to 1.g/kg. The specific conversion depending on the units of concentration used.