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)

16. why must the number of electrons lost equal the number of electrons gained in every redox reaction? use 3 – 4 sentences in your own words to address this question. 18. what type of radiation is emitted when chromium-51 decays into manganese-51? show the nuclear equation that leads you to this answer. 19. a radioactive nucleus alpha decays to yield a sodium-24 nucleus in 14.8 hours. what was the identity of the original nucleus? show the nuclear equation that leads you to this answer.

650.j is the same amount of energy as? 2720cal1550cal650.cal2.72cal

The valence of aluminum is +3, and the valence of the chlorine is -1. the formula fir the aluminum chloride is correctly written as