Measuring the concentration of acids is an essential part of many chemical and industrial processes. It involves determining the concentration of an acid in a solution, which is very important for understanding its chemical properties and reactions.
The most common acids used in chemistry include Hydrochloric acid (HCl), sulphuric acid (H₂SO₄), nitric acid (HNO₃), acetic acid (CH₃COOH) and many more.
Concentration measurements with LiquiSonic® measuring devices
The LiquiSonic®measuring systems enable inline concentration measurements of acids. The measuring technology is able to analyze the components of substance mixtures and can provide information about the concentration or density in real time. The sensors are based on the principle of ultrasonic velocity measurement. They are therefore virtually maintenance-free and can reliably provide measured values even under demanding measurement conditions.
Measuring method from LiquiSonic® for determining the concentration of acids
Our LiquiSonic® measuring systems are based on the principle of sonic velocity measurement and are used in various applications to measure the concentration of different acids.
To determine the speed of sound, a sound pulse is sent through the liquid and the time it takes for the pulse to reach the receiver is measured. As the distance between the ultrasonic transmitter and receiver is constant by design, the speed of sound can be calculated.
Installation of LiquiSonic® measuring systems
LiquiSonic® sensors can be installed directly in the user's system without a bypass, for example in pipelines. There are also different variants that are tailored to specific areas of application and have special properties.
What is an acid?
Acids are chemical compounds that can release hydrogen ions (H+) in aqueous solution. The degree of acidity is measured in the unit pH value, which has a scale from 0 to 14. At a pH value of 7, the solution is neutral and contains the same number of H+ ions as OH- ions. Values below 7 indicate an acidic character, while values above 7 indicate a basic character.
Most acids are soluble in water and can be caustic or corrosive depending on their concentration. An example of an acid is hydrochloric acid, which is widely used in industry and laboratories. It is important to be aware of the properties and effects of acids in order to handle these substances safely and effectively.
Which liquids can be measured?
As important components in numerous production processes, acids must be tested regularly to ensure their efficiency and quality. Various methods can be used to test or improve specific properties.
One of the most commonly used acids is hydrochloric acid (HCl), which is used to clean pipes and tanks. Sulphuric acid (H2SO4), a strong acid, is often used to lower pH values or as a cleaning agent for stainless steel. Other common acids include nitric acid (HNO3), phosphoric acid (H3PO4) and hydrofluoric acid (HF), each with their own specific applications. Choosing the right acid for the testing process depends on the type of liquid and the objectives of the test. The correct application of acids helps to increase the efficiency and quality of process fluids and ultimately improve the quality of the final product.
How do you determine the concentration of an acid?
The concentration of acids can be determined in various ways. Some common methods are
Speed of sound measurement: This method is based on measuring the speed at which sound waves travel through an acid solution. It is particularly suitable for acids with different molecular sizes and structures, as the speed of sound is influenced by these factors.
Titration: In titration, the acid under investigation is mixed with a base of known concentration until a neutralization point is reached. This method is ideal for precise measurements, but is unsuitable for acids that do not react completely with the base or where side reactions occur.
pH measurement: This method measures the concentration of hydrogen ions in the solution to determine the acidity. It is effective with aqueous solutions, but unreliable with very strong acids or in the presence of other ions that may affect the pH meter.
Conductivity measurement: This measures the electrical conductivity of the acid solution, which depends on the ion concentration. This method is useful for ionic acids, but inaccurate for non-ionic or weak acids, as their ions do not contribute sufficiently to the conductivity.
Spectroscopy: Spectroscopic methods, such as UV-Vis spectroscopy, measure the absorption or emission of light in an acid solution. This is suitable for acids that absorb specific wavelengths, but is not suitable for acids without characteristic absorption bands.
Density measurement: The density of an acid solution can provide information about its concentration. This is particularly effective for pure acids or solutions with a known solvent, but is problematic for mixed solutions or if the density is influenced by other dissolved substances.
A classic method is titration, in which a base of known concentration is added to the sample until a neutralization point is reached. This method is often used in the laboratory to determine the exact molarity of an acid. The advantages of titration are its high precision and reliability, while the disadvantages are the need for trained operators and the time-consuming procedure.
Another common method is pH-metry, in which the pH of a solution is measured using a pH meter. This method is often used in industrial processes to monitor the acid concentration in real time. The advantages of pH metry are its quick and easy handling and the possibility of continuous measurement. A disadvantage is the need for regular calibration and maintenance of the pH meter.
Finally, there are spectroscopic methods such as UV/VIS spectroscopy, which are based on the absorption of light of certain wavelengths by acid molecules. This method is used in research and development to determine the concentration of acids in complex mixtures. Spectroscopic methods score points with their ability to detect even very low concentrations, but are much more demanding in terms of the equipment and expertise required.
Applications of acid concentration measurements
In the chemical industry, acid concentration measurements have played a crucial role in a variety of areas and applications. These measurements are of great importance for quality assurance and process control in various industries such as the production of fertilizers, the petrochemical industry, the pharmaceutical industry, the food industry, water treatment and environmental protection, battery production as well as metallurgy and ore processing.
Acid concentration measurements make it possible to monitor the progress of chemical reactions, guarantee product quality and ensure that manufactured products meet the required specifications. In the manufacture of fertilizers, for example, accurate measurement of acid concentration is crucial to ensure that the right nutrients are present in the right quantities. In the petrochemical industry, such measurements help to monitor the effectiveness of catalysts and ensure product purity.
Acid concentration measurements are also indispensable in the pharmaceutical industry. They make it possible to check the effectiveness of medicines and ensure that the correct dosage is administered. In the food industry, such measurements help with quality assurance and control of the acid content in various products. In water treatment and environmental protection, acid concentration measurements are important for monitoring contamination and ensuring water quality.
Acid concentration measurements are also used in battery production, metallurgy and ore processing to monitor the composition of materials and optimize the efficiency of processes.
Overall, acid concentration measurements are essential to ensure product quality, process efficiency and environmental safety in a wide range of applications and industries.
Where is the concentration measurement of acids carried out?
Acid concentration measurement plays an important role in various manufacturing processes. Pipelines in particular represent a critical point, as an excessively high concentration of acids can damage the pipes and lead to leaks. In addition, undesirable chemical reactions can be triggered that affect both the quality of the end product and the safety of employees.
For this reason, regular monitoring of the acid concentration through precise measurements in real time is essential. Various measurement methods, such as pH measurement or ion-selective measurement (ISE), are used for this purpose. The concentration measurement is not only carried out in pipelines, but also at other critical points in the process, such as in tanks or reactors.
