Standard solutions are prepared in college laboratories by the following method. First the solute is measured out into a weighing boat and then transferred into a beaker. The weighing boat needs to be rinsed with distilled water in order to make sure all of the solute has been transferred. Then the beaker is swirled so all of the solute is definitely all dissolved, more water may need to be added and it can also be stirred with a glass rod to do so. This solution is then transferred into the volumetric flask using a glass funnel. The funnel, beaker and glass rod (if used) are then also rinsed a couple of times with distilled water into the flask to ensure no solute is left behind. A stopper is put on the flask and then it gets gently shaken for a further time to make sure all of the solute is dissolved to make the solution. Distilled water is then added to the line measured on the flask. In order not to overshoot a dropping pipette is used to add more at eye level when close to the line until the bottom meniscus reaches the line. The flask is then inverted several times to ensure the solution is homogenous.
Standard solutions in industry are prepared in mostly the same way as they are in college but they are also prepared them using a standard substance (e.g. primary standard). The specified weight of the solute is measured and then this gets diluted with distilled water to a specific volume. In industry they will standardise the solutions against a primary standard.
A similarity between industry and college is that the method of preparing a standard solution are the same. One big difference between preparing standard solutions in college and industry is that primary standards are used in industry. This is because primary standards have high purity and these are used to standardise the solution measurements so as to increase accuracy and make sure that they have the correct concentrations needed. Another difference is that industry uses grade A glassware and analytical balances which are more expensive but colleges use grade B glassware and digital balances. Therefore, the maximum uncertainties of the glassware (including the volumetric flask, pipette etc.) and balances will be smaller and this means the accuracy of the measurements using the glassware will be more accurate. Both of these differences are because of the need for increased accuracy in industry. It is important in industry that the solutions made are extremely accurately to prevent any possible problems caused to people or research if they are not accurate. However, in college it will not cause problems to other people if they are not completely accurate.
When making a titration in college laboratories you first rinse all of the equipment needed. Then you add the standard solution to a conical flask and add in 3 or 4 drops of an indicator. After this the burette is filled to the top (0.0cm) with hydrochloric acid and the stopcock is quickly opened over another beaker to remove any air bubbles that may still be in the burette. Then you put the conical flask under the burette and add the acid whilst swirling until the indicator changes colour. The first titration is always a rough and so does not need to be accurate. The titration needs to be repeated 2/3 times to ensure concordant results and to find the average.
Titrations in industry are carried out the same way that they are in colleges. The precise volume of analyte and indicator is put into a conical flask underneath the burette. Then the titrant is added until the endpoint (indicated by the change in colour) is reached.
In many industries titration is automated and so this makes it faster and much more accurate than having to carry out each by hand. The reason this method gets used in industry is because they may be needing to carrying out many titrations a day so this would reduce the amount of time taken and improve accuracy of the result. Also human error is not a problem since the machine will be able to carry out the titrations very accurately and the result would be worked out digitally which is more precise than having to read it off manually from the burette.
There are different types of titration. One type is the acid-base titration in which the amount of acid or base in a solution is found out. This is done by adding a reagent until the solution reaches a specified pH level (usually 7). You will need a pH meter or a dye to indicate when the pH has been reached. Another type of titration is the redox titration. This works based on the oxidation-reaction reaction between the titrant and analyte. A redox indicator is used to determine the end point.
Titrations are also used in many different industries. For example, the wine industry uses acid-base titrations in order to determine whether or not other ingredients need to be added to the wine. This is done in order to help