To calculate the rate of diffusion of helium gas in air, we can use Graham's law of diffusion, which states that the rate of diffusion of a gas is inversely proportional to the square root of its molar mass. The formula for Graham's law is:Rate / Rate = M / M where Rate and Rate are the rates of diffusion of two gases, and M and M are their respective molar masses.In this case, we want to find the rate of diffusion of helium He in air. Air is primarily composed of nitrogen N and oxygen O , with molar masses of 28 g/mol and 32 g/mol, respectively. We can approximate the molar mass of air as the average of nitrogen and oxygen, which is:M_air 28 g/mol + 32 g/mol / 2 = 30 g/molThe molar mass of helium He is 4 g/mol. Now we can use Graham's law to find the rate of diffusion of helium in air:Rate_He / Rate_air = M_air / M_He Let's assume the rate of diffusion of air is 1 this is just a reference value, as we are interested in the relative rate of helium compared to air . Then:Rate_He / 1 = 30 g/mol / 4 g/mol Rate_He = 7.5 Rate_He 2.74So, the rate of diffusion of helium gas in air at 25C and a pressure of 1 atm is approximately 2.74 times faster than the rate of diffusion of air.