The potential energy of a molecule on the surface of a liquid compared to one inside the liquid is

$A$ soap bubble of radius $r$ is blown up to form a bubble of radius $2r$ under isothermal conditions. If $T$ is the surface tension of the soap solution, what is the energy spent in blowing the bubble (in $\pi T r^2$)?

The radius of a soap bubble is $r$, and the surface tension of the soap solution is $T$. Without increasing the temperature, how much energy is required to double its radius (in $\pi r^2 T$)?

The surface tension of a liquid is $5 \, N/m$. If a thin film of the area $0.02 \, m^2$ is formed on a loop,then its surface energy will be

The surface tension of a soap solution is $0.03 \,N/m$. The work done in blowing to form a soap bubble of surface area $40 \,cm^2$ (in $J$) is: