1) Predict the sign, (+) or (-), for H and S for the following reactions. 2 C(s)
ID: 1064444 • Letter: 1
Question
1) Predict the sign, (+) or (-), for H and S for the following reactions.
2 C(s) + O (g) 2CO(g) H: _____ S: _____
CO2 (s) CO2 (g) H: _____ S: _____
N2(g) + 3H2(g) 2NH3(g) H: _____ S: _____
2) Use the standard entropy values below to calculate the entropy change (Sorxn) for the following balanced equation. N2 (g) + 2 O2 (g) --> 2 NO2 (g)
Species So , (J/K*mol)
N2(g) 191.5
O2(g) 205.0
NO2(g) 240.0
3) A reaction for which H and S are both negative will be:
a. spontaneous at high temperatures.
b. spontaneous at low temperatures.
c. spontaneous at all temperatures.
d. never be spontaneous
e. more information is needed to determine spontaneity.
Answers I got: 1) - + , + - , + - 2) -121.5 3) I think its A.
Thanks
Explanation / Answer
Q1.
1) Predict the sign, (+) or (-), for H and S for the following reactions.
2 C(s) + O (g) 2CO(g) H: _____ S: _____
dH must be NEGATIVE, since this is combustion, which releases heat
dS --> entropy must increases since 1 mol of gas forms 2 mol of gases, which is more chaotic
CO2 (s) CO2 (g) H: _____ S: _____
This is sublimation, it require energy to go from solid to energy, so this must be positive, endothermic
dS --> increases since gas is much more chaotic than solid
N2(g) + 3H2(g) 2NH3(g) H: _____ S: _____
This is dH = negative, since bonds are broken and energy is released
dS --> 4 mol of gas form 2 mol of gas, chaos decreases so dS must be negative
For all further questions, please post multiple questions in multiple set of Q&A. We ar enot allowed to answer to multiple questions in a single Q&A post.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.