How do we predict the conditions (high temperature, low temperature, all temperatures, or no temperatures) under which each of the following reactions will be spontaneous. (I have the correct answers to the following so I really want to understand how to solve this question or approach it - Thank you)

a) H2O(g) -->H2O(l)

b) CO2(s)-->CO2(g)

c) H2(g)-->2H(g)

d) 2NO2(g)-->2NO(g)+O2(g)(endotherm ic)

2b2t

explanation:

2b2t

it would be b. 6co2 + 6h2o --> c6h12o6 + 6o2

on passing the small ampere of electric current through the tube made of ar and hg of cfl generates uv rays which excites the fluorescent and thus emits the high radiation by consumption of just 5- 12 w in comparison to incandescent light which requires more power such as around 40 - 55 w to lighten.

moreover the life span of fluorescent or cfl is around 8000 h whereas the life span of incandescent is around 1200 h

hence, the building installed with incandescent lights bears more electricity bill.