Will mark brainliest! explain why a mechanical wave does not exist in a vacuum.

baking soda is a solid.

answer:

δh > 0; δs > 0; δg = 0

not spontaneous when t < 100 °c;

          equilibrium when t = 100 °c

      spontaneous when t > 100 °c

step-by-step explanation:

the process is

h₂o(ℓ) ⇌ h₂o(g)

δh > 0 (positive), because we must add heat to boil water

δs > 0 (positive), because changing from a liquid to a gas increases the disorder

δg = 0, because the liquid-vapour equilibrium process is at equilibrium at 100 °c

δg = δh – tδs

both δh and δs are positive.

if t = 100 °c, δg =0. δh = tδs, and the system is at equilibrium.

if t < 100 °c, the δh term will predominate, because t has decreased below the equilibrium value.

δg > 0. the process is not spontaneous below 100 °c.

if t > 100 °c, the tδs term will predominate, because t has increased above the equilibrium value.

δg < 0. the process is spontaneous above 100 °c.