Chemical Bonding And Molecular Structure

Step 1: Use shape to judge polarity.
SO is bent (V-shaped); its bond dipoles do not cancel molecule is polar.
Step 2: Eliminate others.
SO (trigonal planar), BF (trigonal planar) and CO (linear) have symmetric geometries overall non-polar.
Step 3: Conclusion.
Therefore, the polar compound here is SO .

Step 1: Use molecular geometry.
CCl is perfectly tetrahedral and all C–Cl bond dipoles cancel due to symmetry.
Step 2: Eliminate others.
CH Cl, CHCl , and CH Cl are polar because the vector sum of their bond moments is non-zero.
Step 3: Conclusion.
Hence, CCl has zero dipole moment.

Step 1: Understanding bond energies.
Bond energy refers to the energy required to break a bond between two atoms. As the atomic size increases, the bond energy typically decreases because the bonding atoms are farther apart. Step 2: Analysis of options.
(A) O - O: The oxygen-oxygen bond in O₂ is relatively weak, but it has the highest bond energy among the options listed.
(B) S - S: The sulfur-sulfur bond in is weaker than the oxygen-oxygen bond.
(C) Se - Se: Selenium-selenium bonds are weaker than sulfur-sulfur bonds.
(D) Te - Te: The tellurium-tellurium bond is the weakest of all the listed bonds.
Step 3: Conclusion.
The correct answer is (A) because the oxygen-oxygen bond has the highest bond energy among these elements.

Step 1: Understanding bond angles.
The bond angle in a molecule is influenced by the size of the central atom. As the size of the atom increases, the bond angle generally decreases due to the increased repulsion between lone pairs of electrons. Step 2: Analysis of options.
(A) : Water has a bent shape with a bond angle of approximately 104.5°, which is the smallest among the options due to lone pair repulsion.
(B) : Hydrogen sulfide has a bond angle of around 92°, which is larger than water's bond angle.
(C) : Hydrogen selenide has a bond angle of around 91°, slightly larger than H₂S.
(D) : Hydrogen telluride has a bond angle of around 90°, which is the largest among the given molecules.
Step 3: Conclusion.
The correct answer is (A) because has the smallest bond angle due to its smaller central atom and stronger lone pair repulsion.

Step 1: Identify chloral.
Chloral is an organic compound with the formula CCl CHO, consisting of a trichloromethyl group (CCl ) attached to an aldehyde group (CHO). It is commonly used in the synthesis of chloral hydrate.
Step 2: Analyze the options.
- CCl CHO is the correct structure for chloral. - The other options are different compounds with varying groups attached to the trichloromethyl group but do not represent chloral.
Step 3: Apply to the options.
The correct formula for chloral is (A) CCl CHO.
Final Answer:

Step 1: Understand the molecular structure of oxygen.
Oxygen (O ) has 8 electrons in its outermost shell, and each oxygen atom contributes 8 electrons, for a total of 16 electrons in the O molecule.
Step 2: Apply the molecular orbital theory.
- According to the molecular orbital theory, oxygen molecules (O ) have two unpaired electrons in the antibonding orbitals. - These unpaired electrons result in the paramagnetic behavior of O .
Step 3: Apply to the options.
The number of unpaired electrons in one molecule of liquid oxygen is 2, so option (B) is correct.
Final Answer: