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Making Normal Solutions from Concentrated Acids Tim Loftus The last article covered the concept of Normal solutions in the laboratory and how to calculate the equivalent mass of a compound. Then I described how to use the equivalent mass to make a solution of a predetermined Normality.
However, the article did not address making Normal solutions from concentrated mineral acids like sulfuric acid, nitric acid, and hydrochloric acid.
Unlike using powdered chemicals where the chemical is simply weighed out then diluted to volume, the use of liquid chemicals to make Normal solutions requires the addition of a few more calculations.
This article will address these extra calculations. First, it is important to describe a few aspects of concentrated mineral acids as well as that of many other solutions. Most of us buy concentrated acids to use as stock solutions in the laboratory. None of these acids are one hundred percent pure.
Manufacturers of these acids simply cannot economically make these acids more concentrated than these respective percentages. Another important aspect of these solutions is their specific gravities.
The specific gravity of a liquid is, in most cases, synonymous with the more familiar term of density. Water has a specific gravity of 1. If the specific gravity of a liquid is greater than 1, then the liquid is heavier than water.
Less than 1, and the liquid is lighter than water. The specific gravity for concentrated sulfuric acid is about 1.
The specific gravity of concentrated nitric acid is about 1. Both the percent concentration and specific gravity values of the acid are required to determine the amount of concentrated acid needed when making a Normal solution.
This information is usually printed on a label attached to the bottle of acid. Specific values vary depending on the manufacturer and lot of acid. To make a solution of a predetermined Normality, you must first determine the equivalent mass of the chemical and then determine the grams needed of that chemical.
Once this volume is determined, it is a simple dilution after that. Here is an example: How many milliliters of concentrated sulfuric acid do you need to make mL of a 1 N solution?
To determine how many grams of sulfuric acid you will need, you will first need to calculate the equivalent mass of H2SO4. This is the gram-formula weight divided by the number of acid hydrogens in the compound. Then you can calculate the amount of grams of H2SO4 that are needed.
The formula to calculate this is: Substituting the above numbers into the equation, we get: A 1 N solution requires But the acid is a liquid and it is not one hundred percent pure active sulfuric acid. You will need to calculate what volume of the concentrated acid that contains The formula for this is: For this example, I am using those values previously mentioned in this article: Always add the acid or base to water, in that order.
Pour slowly with constant mixing.Therefore, if the liquids you’re testing are acids, the BLUE litmus will turn RED. Acids and Bases Most of the liquids that you see have either acidic of basic properties. We know some Lab: Testing common liquids to classify as acids or bases.
LAB -Chap Properties of Acids & Bases ANSWERS IN THIS COLOR Purpose: Reactions in aqueous solution in which protons are transferred between species are called acid/base ashio-midori.coml properties of acid/base chemistry will be qualitatively studied in this experiment.
Testing for Acids and Bases– Group Lab report on pH. More details on lab report grading policy. The indicator is a compound that can provide different colors in . Learn and research science, chemistry, biology, physics, math, astronomy, electronics, and much more.
ashio-midori.com is your scientific resource and internet science PORTAL to . Acids and Bases Quiz You got: % Correct. pH Phailure yellowdog / Getty Images Okay, so this whole acids, bases, and pH thing is either new to you or else boring you to tears.
All living things contain organic macromolecules: Lipids, proteins, carbohydrates and nucleic acids. Characteristic for these organic molecules is that they are made up of only a small number of elements: carbon, hydrogen, oxygen, and to smaller amounts nitrogen, phosphorus and sulfur.