Lec 1 Q Ph.Ph.

interface is the boundary between two phases one of them is gas

• True

• False

Heating the liquid tend to

• increase the surface tension

• decrease the surface tension

• decrease the distance between molecules

• increase the cohesive force

Methods to determine the surface tension

• cappillary rise methos

• drop count method

• drop weight method

• all of them

Considering liquid with high surface energy, which of the following is TRUE

• droplet size tends to increase

• cohesive force is weak

• surface tension is high

• temperature has no effect on this liquid

what is the surface tension of water?

• 62.8 dyne/cm

• 1 dyne/cm

• 72.8 dyne/cm

• 100 dyne/cm