Group 18 is known as the Noble/ Inert Gases
CH4 is <u>not</u> soluble in water
whereas CH3OH <u>is</u> soluble in water.
Answer:
C. ΔG is positive at low temperatures, but negative at high temperatures (and zero at some temperature).
Explanation:
Since we need to give energy in the form of heat to vaporize a liquid, the enthalpy is positive. In a gas, molecules are more separated than in a liquid, therefore the entropy is positive as well.
Considering the Gibbs free energy equation:
ΔG= ΔH - TΔS
+ +
When both the enthalpy and entropy are positive, the reaction proceeds spontaneously (ΔG is negative) at high temperatures. At low temperatures, the reaction is spontaneous in the reverse direction (ΔG is positive).
Evaporation!
-Melting is a solid to a liquid
-sublimation is directly from a solid to a gas
-condensation gas to liquid
