مائعات

Written by Dr. Ayesha Nadeem (Chemistry)

گیارہویں جماعت · کیمیا · 8 سوالات

نام: ____________________ تاریخ: ____________

Boiling point of a liquid is the temperature at which its vapour pressure equals the:
- A Osmotic pressure
- B Atmospheric pressure
- C Zero
- D Critical pressure
Hydrogen bonding is strongest in:
- A HCl
- B H2S
- C CH4
- D H2O
Surface tension tends to:
- A Minimise the surface area
- B Increase the surface area
- C Increase temperature
- D Remove cohesion
The viscosity of a liquid decreases when it is:
- A Heated
- B Compressed
- C Cooled
- D Frozen
London dispersion forces are present in:
- A All molecules
- B Only polar molecules
- C Only ions
- D Only metals
A liquid with weak intermolecular forces has a:
- A High surface tension
- B Low boiling point
- C High viscosity
- D High boiling point
Capillary action is due to:
- A Magnetism
- B Adhesion and cohesion
- C Gravity only
- D Heat
The process in which a liquid changes to vapour only at its surface is:
- A Condensation
- B Boiling
- C Sublimation
- D Evaporation

جوابی کلید

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

A liquid boils when its vapour pressure equals the external pressure.
Water has O-H bonds that form strong hydrogen bonds.
It pulls a liquid surface to the smallest area, giving droplets their round shape.
Heating weakens attractions between molecules.
Dispersion forces exist between all molecules and atoms.
Little energy is needed to separate the molecules.
Liquid rises in narrow tubes.
Evaporation occurs at the surface at any temperature.