How many grams of Ca(OH)2 are needed to make 100.0 mL of 0.200 M solution

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.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.