کیمیائی بندھن اور سالمے کی شکل

Written by Dr. Ayesha Nadeem (Chemistry)

ایم ڈی کیٹ · کیمیا · 8 سوالات

نام: ____________________ تاریخ: ____________

What is the shape of the ammonia (NH3) molecule?
- A Trigonal planar
- B Tetrahedral
- C Linear
- D Trigonal pyramidal
Which molecule is linear?
- A Ammonia (NH3)
- B Water (H2O)
- C Methane (CH4)
- D Carbon dioxide (CO2)
What is the hybridisation of each carbon atom in ethene (C2H4)?
- A sp
- B sp3
- C sp2
- D sp3d
The unusually high boiling point of water is mainly due to:
- A Hydrogen bonding
- B Ionic bonding
- C Metallic bonding
- D Covalent bonds in water being weak
Which of these is an ionic compound?
- A Sodium chloride
- B HCl gas
- C Carbon dioxide
- D Methane
How many sigma and pi bonds are there in ethyne (C2H2)?
- A 5 sigma and no pi
- B 4 sigma and 1 pi
- C 3 sigma and 2 pi
- D 2 sigma and 3 pi
Which of these molecules is polar?
- A BF3
- B CO2
- C H2O
- D CH4
The bond angle in a water molecule is about:
- A 90 degrees
- B 104.5 degrees
- C 109.5 degrees
- D 120 degrees

جوابی کلید

1. D, 2. D, 3. C, 4. A, 5. A, 6. C, 7. C, 8. B

Nitrogen has three bond pairs and one lone pair. The lone pair pushes the bonds into a pyramid shape.
CO2 has two double bonds and no lone pairs on carbon, so the molecule is a straight line (180 degrees).
Each carbon forms three sigma bonds and one pi bond, which uses sp2 hybrid orbitals.
Hydrogen bonds between water molecules need a lot of energy to break, so water boils at a much higher temperature than similar small molecules.
Sodium chloride is formed by transfer of an electron from sodium to chlorine. The others are covalent.
The C-C triple bond has one sigma and two pi bonds. Add two C-H sigma bonds and the total is 3 sigma and 2 pi.
Water is bent, so the bond dipoles do not cancel. CO2, CH4 and BF3 are symmetrical and non-polar.
Two lone pairs on oxygen squeeze the H-O-H angle to about 104.5 degrees, smaller than the tetrahedral 109.5.