Question

Two soap bubbles A and B are kept in a closed chamber where the air is maintained at pressure 8N/m^2 The radii of bubbles A and B are 2cm and 4cm, respectively surface tension of the soap water used to make bubbles is 0.04N/m If nA and nB are the no of moles of air in the air bubbles A and B, then the ratio nB/nA is [Neglect the effect of gravity]

Answer 1

Explanation:

Excess pressure for soap bubble, ΔP=R4T  where T= surface tension.

Here, PA=P0+RA4T=8+0.024(0.04)=16N/m2

and PB=P0+RB4T=8+0.044(0.04)=12N/m2

As PV=nRt,n∝PV

Thus, nBnA=PBVBPAVA=12×(4/3)π(0.04)316×(4/3)π(0.02)3=1/6

∴