Q1: A long cylinder and a sphere both of 5 cms diameter are made from the same porous material. The flat ends of cylinder are sealed. Both the cylinder and sphere are saturated with the same solution of sodium chloride. Later both the objects are immersed for a short and equal interval of time in a large tank of water which is well agitated. The fraction of salt remaining in the cylinder and the sphere are X_c and X_s respectively. Which of the following statement is correct ?

ANS:C - X_c < X_s

The rate at which the salt diffuses out of the porous material depends on the surface area through which diffusion can occur. In this scenario, both the cylinder and the sphere are made of the same porous material and have the same diameter (5 cm), so they have the same surface area. When the objects are immersed in water, the salt diffuses out of them through their surfaces. Since both objects have the same surface area, the rate of diffusion of salt out of the cylinder and the sphere should be the same, assuming all other factors remain constant. Therefore, the fraction of salt remaining in the cylinder (𝑋𝑐Xc​) should be equal to the fraction of salt remaining in the sphere (𝑋𝑠Xs​). So, the correct statement is: 𝑋𝑐=𝑋𝑠Xc​=Xs​