question_answer

At which of the following temperature, the value of surface tension of water is minimum?             

A)  \[{{4}^{o}}C\]                

B)  \[{{35}^{o}}C\]                       

C)  \[{{60}^{o}}C\]            

D)  \[{{75}^{o}}C\]

Correct Answer: D

Solution :

The surface tension of water is 72 dyne/cm at \[{{25}^{o}}C\]It would take a force of 75 dyne to break a surface film of water 1cm long. The surface tension of water decreases significantly with temperature as shown in the graph below: Out of the given four option \[75{}^\circ C\] is the highest temperature, hence, surface tension is lowest.