What is R in chemistry?

Answer 1

In organic chemistry and biochemistry, the symbol R denotes a side chain. (The symbol in fact stands for radical.) This is useful when you wish to write a single formula to denote a number of different compounds with a certain structure in common.

Example

All the amino acids that are encoded by DNA have this component: -CH(NH2).CO2H

A convenient way to write the formula for all these amino acids is:

R-CH(NH2).CO2H

where

R = hydrogen (H-) in the amino acid glycine

R = a methyl group (CH3-) in alanine

and so on.

Answer 2

In chemistry, R usually represents the general symbol for an alkyl group, which is a group of atoms derived from an alkane by removing one hydrogen. It is commonly used in organic chemistry to represent any alkyl group in a molecule, where the specific alkyl group can vary.

Answer 3

In organic chemistry R means hydrocarbon Alkyl group, such as methly, ethyl, propyl, butyl, (straight or branched chains) or possibly rings such as cycloalkyl, In physical chemistry "R" means Gas constant .

Answer 4

For chemists, the R / S system is the most important nomenclature system for denoting enantiomers, which does not involve a reference molecule such as glyceraldehyde. It labels each chiral center R or S according to a system by which its substituents are each assigned a priority, according to the Cahn-Ingold-Prelog priority rules (CIP), based on atomic number. If the center is oriented so that the lowest-priority of the four is pointed away from a viewer, the viewer will then see two possibilities: If the priority of the remaining three substituents decreases in clockwise direction, it is labeled R (for Rectus, Latin for right), if it decreases in counterclockwise direction, it is S (for Sinister, Latin for left).