What is the empirical formula for 27.3% and 72.7% oxygen?

27.3% of Carbon (C), 72.7% of Oxygen (O).

answer: the rate of diffusion increases with increase in temperature.

increase in temperature, increases the molecular/particles speed (kinetic energy. diffusion means movement of particles through the material.

generally, the heavier the particle the more it interacts with the environment and more the temperature matters. so higher temperature results in higher diffusion.

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.