True or false questions in general chemistry??

Question

Determine whether the following statements about heats of reaction are true or false.

A) The heat of reaction is sometimes the change in internal energy.
B) The heat of reaction is the sum of the standard heats of formation of the products minus the sum of the standard heats of formation of the reactants.
C) You can calculate the heat of reaction from standard heats of formation.
D) The standard heat of formation of carbon (graphite) at 25 degC is zero.
E) The standard heat of formation of all elements at 1 atm and 25 degC is zero.


I think D, E, and possibly B or True but I'm not certain, on the others I have no clue.

Please help, Thank You

Answer 1

A. ∆E=∆H - P∆V, so if ∆V = 0, is correct. For a reaction in which there is no change in volume, ∆E = ∆H.
B. ∆Hrxn = ∑∆Hf (products) - ∑∆Hf (reactants), so it is correct.
C, D and E are also correct. So every answer is correct.

Answer 2

False
Tru
False
True
True

Answer 3

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Answer 4

B, C,and D are true and the rest are false

Answer 5

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Answer 6

E is true.

Answer 7

F

Answer 8

you're correct

Answer 9

a;-f
b-f
c-t
d-f
e-f