Which of the molecules below will be polar? cs2. bf3. so2. ch3br

Which of the molecules below will be polar? CS2, BF3, SO2, CH3Br

CH3Br only
CS2 only
Both BF3 and CH3Br
Both SO2 and CH3Br

Answer

General guidance

Concepts and reason
For the given molecules, draw the structures based on the VSEPR. Identify the polar bonds in the molecules. Also check for the lone pair present in the molecule. Presence of polar bonds and lone pair indicate that polarity is present in the molecule. Unsymmetrical molecules also have polarity.

Fundamentals

Valence Shell Electron Pair Repulsion Theory(VSEPR) is used to predict the geometry of a molecule. This theory is based on the electrostatic repulsion. The lone pairs and bond pairs present in the molecule arrange themselves in a way that they experience minimum repulsion. The sequence followed to determine the repulsive order is as follows: Lone pairlone pair Lone pairbond pair Bond pairbond pair The lone pairs and bond pairs present in the molecule arrange themselves in a way that they experience minimum repulsion. Polar nature arises in a molecule due to the difference in the electronegativity of the bonded elements. The electronegative element pulls the electron cloud of the bonded electrons towards itself. This behaviour develops a small negative charge on the more electronegative element. The bond formed by the elements having difference in electronegativity give rise to a polar molecule. When the molecule is unsymmetrical, the structure of the molecule gives rise to the polarity of the molecule.

Step-by-step

Step 1 of 2

The structure of the given molecules is drawn as follows: S=CES
cugere
som
CHBr
SO2
CS2

The shape of the given molecule is as follows: 1.: Tetrahedral The shape of is tetrahedral. It is an unsymmetrical molecule. The central carbon atom is bonded to three hydrogen atoms and on bromine atom. Bromine atom is more electronegative than carbon, thus, the C-Br bond is polar. 2.: Bent The shape of is bent. The shape is changed from linear to bent due to the presence of lone pair on sulphur. 3.: Trigonal planar. The shape of is trigonal planar. It is a symmetrical molecule. The central boron atom is bonded to three fluorine atoms. 4.: Linear. The shape of is linear. It is a symmetrical molecule.

Step 2 of 2

The molecules with the polarity are shown as follows: F1
1-12 人-
S
-C
-S
- CH₃Br
CHBr
502
BE
BF3
CS₂
CS2

Among the given molecules, the polar molecules are as follows: • CH3Br only.
CS2 only.
Both BFZ and CHZBr.
Both SO2 and CH3Br.


has a polar bond due to the electronegativity difference between the carbon and bromine atom. is unsymmetrical in nature. Therefore, is polar in nature. has a lone pair of electron on the central sulphur atom. Due to the presence of lone pair, the shape of is bent and the polarity is developed in the molecule.

Answer

Among the given molecules, the polar molecules are as follows: • CH3Br only.
CS2 only.
Both BFZ and CHZBr.
Both SO2 and CH3Br.

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