Question Discussion & Solution

The correct answer is carbon.

Key Points

• A fullerene is an allotrope of carbon whose molecule consists of carbon atoms connected by single and double bonds so as to form a closed or partially closed mesh, with fused rings of five to seven atoms.
  • The molecule may be a hollow sphere, ellipsoid, tube, or many other shapes and sizes.
• Various allotropes of carbon are diamond, graphite, lonsdaleite, fullerene, C-540, C-70, amorphous carbon, carbon nanotube.
• Diamond and crystalline silicon are isomorphous because they both have a three-dimensional tetrahedral structure.
• Allotropy, the existence of a chemical element in two or more forms, which may differ in the arrangement of atoms in crystalline solids or in the occurrence of molecules that contain different numbers of atoms.

Additional Information

• When an element exists in more than one crystalline form, those forms are called allotropes; the two most common allotropes of carbon are diamond and graphite.
  • One of the allotropic form of a carbon is a fullerene in which “carbon atoms” are “arranged in a sphere”.
  • Each sphere has 60 carbon atoms and each carbon atom is linked by a single covalent.
  • The fullerene is considered as purest allotrope of “carbon” because they have “smooth structure” without having dangling bonds.

Arrow moves one, two, three, four, and five sequentially anticlockwise. The arrow head change in a sequence of filled circle → Filled arrow → Open arrow

Next figure is gap of five with open arrow. 

The correct answer is 1 i.e. propanal.

Concept:

IUPAC nomenclature:

• A systematic method of naming organic compounds.
• Naming is based on their structures.
• It is devised by the International Union of Pure and Applied chemistry.
• Many rules are followed while naming the compounds and it is different for different functional groups.
• The rules are known as IUPAC rules.

Explanation:

• This compound contains 3 carbon atoms, so its parent alkane is propane.
• It also contains an aldehyde group (-CHO-) group which is indicated by using 'al' as suffix or ending.
• So by replacing the last 'e' of butane with 'al', the name becomes propanal.
• Thus, the IUPAC name of the compound CH3CH2CHO is propanal.
• The common name of propanal is Propionaldehyde.

​Additional Information

• The chart for priority order and suffix name is given below:

Four members: A, B, C, D

Using the symbols in the table given below, we can draw the following family tree:

1) B is the husband of A

2) C is the sister of B

3) D is the brother of A

Hence, C is D’s brother-in-law's sister.

The correct answer is Lactometer.

• Some other important measuring instruments are: