Tag: Chemist

How do we understand the classification of Colloids ?

In surface chemistry, the word colloid refers to a colloidal solution which is an intermediary between true solution and suspension.

In absorption, a substance enters another substance and gets distributed uniformly throughout the 2nd substance.

A compound comprises two or more than elements, and the chemistry formula reveals the number of atoms present in each component. The chemical formula contains symbols of the element’s atoms in the compound. It also reflects the number of atoms present in each element.

Dmitri Mendeleev was one of the great chemists of the 19th century. He correctly predicted the properties of more than three undiscovered elements. His contributions to chemistry won him the title of the father of the modern periodic table.

Robert Boyle was a chemist of the 17th century and a founder of the modern chemistry.

The law of conservation of matter is a fundamental law in science. It is also known as the law of conservation of mass. The later is used in physics while the former in chemistry. It is one of the laws of chemical combinations in chemistry. The law has huge applications in chemistry, physics, and engineering. In a closed system, the exchange of matter is restricted across its boundaries. So, there is no matter entering the system or leaving the system. Thus, the flow of matter in and out of the system is zero. These statements are true only for a closed system with no nuclear change. We can apply the law to systems which are subjected to physical and chemical changes, not nuclear changes. This will be better understood as we go through the article.

Accuracy refers to the closeness between the measured value and actual value of a quantity. While precision indicates closeness among the measured values of a quantity. Accuracy indicates how much the measured value agrees with actual value, and precision indicates how close the measured values agree among themselves. The results which are easily reproducible have good precision.

In chemistry, we may deal with different varieties of calculations. Sometimes, we may come across very large numbers like Avogadro’s constant (N_A = 6.022 × 10²³ mol⁻¹), or sometimes, with very small numbers like the diameter of hydrogen (120 pm). Many times, chemistry experiments involve the handling of large experimental data like vapour pressure data. So, there is a need for the right technique to manage numbers conveniently and maintain the accuracy of numbers. This is where the concept of significant figures arises.

To maintain consistency in SI units, the International System of Units has adopted specific rules and style conventions for writing SI units. General rules for writing SI units were first specified by the 9th CGPM in 1948. Later, various international bodies like ISO extended these rules. These rules are very important in scientific writing. Adherence to these rules is strictly recommended while submitting and reviewing a manuscript. The general guidelines are described below.