The value of surface tension of a liquid at critical temperature is

There is a horizontal film of soap solution. On it,a thread is placed in the form of a loop. The film is pierced inside the loop,and the thread becomes a circular loop of radius $R$. If the surface tension of the soap solution is $T$,what will be the tension in the thread?

If the surface area of the soap solution is increased,then its surface tension

What is the effect of increasing temperature on surface tension?

If the work done in increasing the size of a soap film from $10\;cm \times 6\;cm$ to $10\;cm \times 11\;cm$ is $2 \times 10^{-4}\;J$,then the surface tension is:

What is the ratio of the surface tension force acting on the curved part to that on the flat part?