Cortisone is a molecular substance containing 21 atoms of carbon per molecule. The mass percentage of carbon in cortisone is 69.98 %. What is the molar mass of cortisone ?

In cortisone $69.98 \,g C \equiv 100\, g$ cortison $1$ mole of cortisone contains $21$ moles of carbon atoms or $252\, g$ of carbon $252 \,g $ carbon $\equiv $ 1 mol cortisone $69.98\, g$ carbon $\frac={69.98}{252}$ mol cortisone $\frac{69.98}{252}$ mol cortisone $\equiv 100 \,g$ 1mol cortisone $=\frac{100\,g \times 252}{69.98}=360.10\,g$ $\therefore$ Molar mass of cortisone $= 360.10 \,g\, mol^{-1}$

Cortisone is a molecular substance containing 21 a

Notes on Some basic concepts of chemistry

Concepts Used:

Some Basic Concepts of Chemistry

Chemistry is a vast subject and for understanding its significance we can take help of following points:

Chemistry plays an important role in understanding various subjects like physics, geology and biology.
Chemistry is a core branch of science that explains us about the various compositional properties and interaction of matter. It also helps to understand various chemical reactions.
Chemistry is important in order to understand the behaviour of fertilizers, alkenes, acids, salts, dyes, polymers, drugs, soaps and alloys in organic and inorganic chemistry.
Chemistry plays an important role in various fields like healthcare, industrial, research, food, and farm activities.

Classification of Matter

There are two ways of classifying the matter:

(A) Physical Classification:

Matter can exist in three physical states:

Solids - have definite volume and definite shape
Liquids - have definite volume but not definite shape.
Gases - have neither definite volume nor definite shape.

(B) Chemical Classification:

Based upon the composition, matter can be divided into two main types:

Pure Substances are defined as a single substance (or matter) which cannot be separated by simple physical methods. Pure substances can be further classified as (i) Elements (ii) Compounds
Mixtures are the combination of two or more elements or compounds which are not chemically combined together and may also be present in any proportion.