If we heat a partially filled closed container with liquid in it, will the relative humidity ever reach 100% (assuming that the vessel is strong enough to hold infinite amount of pressure). I have read that as temperature increases the moisture carrying capacity of the air will increase hence as long as we don't add vapor to air the relative humidity will increase. But since in a closed container the temperature of the liquid also keeps on increasing, more amount of molecules are turning from liquid state to the gaseous state as well.
In a closed container at equilibrium the relative humidity is always 100%. The liquid evaporates until the partial pressure of the vapor reaches the maximum value. If the temperature is increased the (maximum) vapour pressure increases and more liquid evaporates until the partial pressure of the vapors reaches the new vapor pressure. And is again 100% relative humidity at the new equilibrium state. If course, if there is enough liquid in the container to have both phases at equilibrium.