Question

Identify the term or substance based on the descriptions given below:
1.Ice like crystals formed on cooling an organic acid sufficiently.
2.Hydrocarbon contains a triple bond used for welding purposes.
3.The property by virtue of which the compound has the same molecular formula but different structural formula.
4.The compound formed where two alkyl groups are linked by \[-CO - \] group

Answer 1

Hint: The ice-like crystals which are formed on cooling an organic acid are pure ethanoic acid whose melting point is 290 K. Alkynes are unsaturated hydrocarbons containing a triple bond between two carbon atoms.

Complete step by step answer:
1.Ice like crystals formed on cooling an organic acid sufficiently.
When glacial acetic acid is cooled sufficiently then the ice like crystals are formed.
These ice like crystals which are formed on cooling an organic acid is pure ethanoic acid whose melting point is 290K and hence it often freezes during winter in cold climates, therefore it is known as glacial acetic acid. Glacial acetic acid is undiluted acetic acid.
2.Hydrocarbon contains a triple bond used for welding purposes.
Alkynes are unsaturated hydrocarbons because its two carbon atoms are bonded together in a triple bond. The carbon–carbon triple bond places all four atoms in the same straight line, with CCH bond angles of \[180^\circ \] . Acetylene is an essential alkyne and the compound finds its use for many different purposes such as arc welding.
Acetylene (ethyne) is the chemical compound with the formula \[{C_2}{H_2}\] , a hydrocarbon and it is the simplest alkyne. It is a colourless gas (lower hydrocarbons are generally gaseous in nature)
Thus, acetylene is used for welding.
3.The property by virtue of which the compound has the same molecular formula but different structural formula. This property is Isomerism by virtue of which the compound has the same molecular formula but different structural formulae.
4.The compound formed where two alkyl groups are linked by \[-CO - \] group. The compounds formed, when two alkyl groups are linked by \[-CO - \] group are Ketones.

Its example can be acetone.

Note: Acetylene is also widely used as a fuel and a chemical building block. It is unstable in its pure form and thus can be usually handled as a solution. Pure acetylene is odourless, but commercial grades usually have a marked odour due to impurities.