## Ice melting

$\Delta G^{\circ}= \Delta H^{\circ} - T \Delta S^{\circ}$

$\Delta G^{\circ}= -RT\ln K$

$\Delta G^{\circ}= \sum \Delta G_{f}^{\circ}(products) - \sum \Delta G_{f}^{\circ}(reactants)$

Hailey Boehm 2H
Posts: 71
Joined: Fri Sep 28, 2018 12:24 am

### Ice melting

Why is ice melting a spontaneous process? Also, why is the combustion of gas spontaneous?

A De Castro 14B 2H
Posts: 75
Joined: Fri Sep 28, 2018 12:29 am

### Re: Ice melting

Ice melting is a spontaneous process because the order of the water molecules is interrupted, meaning that entropy increases (+∆S). Even though it requires energy (endothermic, +∆H), the reaction usually occurs in high temperatures, resulting in -∆G. The combustion of a natural gas is spontaneous because of a negative ∆H and positive ∆S, which leads to negative ∆G.

Joanna Pham - 2D
Posts: 113
Joined: Fri Apr 06, 2018 11:04 am

### Re: Ice melting

I like to think of spontaneity as the ability of a reaction to occur on its own, meaning that the reaction does not require additional energy in order for the reaction to take place

Noah Fox 1E
Posts: 31
Joined: Fri Sep 28, 2018 12:20 am

### Re: Ice melting

The melting of ice is spontaneous because its something that occurs naturally (in the right temperature). The way I like to think about it is that in an area with high heat the ice cube (devoid of heat) will naturally see energy diffuse into the ice breaking the bonds at the same time. The combustion of gas is spontaneous because it breaks complex organic molecules and breaks it into smaller pieces.

Ashley P 4I
Posts: 64
Joined: Wed Nov 15, 2017 3:04 am

### Re: Ice melting

There was a question on Test Two about dry ice being left in a room at room temperature. Would that also be a spontaneous reaction? Because it is moving towards becoming vaporized?