A

Please see the attached file.

16. Which of the following statements is incorrect?
A.
The thermochemical standard state of a substance is its most stable state under one atmosphere pressure and at some specific temperature (298 K if not specified)
B.
A superscript zero, such as H0, indicates a specified temperature of 0C. Incorrect, normally means 25oC
C.
For a pure substance in the liquid or solid phase, the standard state is the pure liquid or solid.
D.
For a pure gas, the standard state is the gas at a pressure of one atmosphere.
E.
For a substance in solution, the standard state refers to one-molar concentration.

17. Fuel values of hydrocarbons increase as the H/C atomic ratio increases. Which of the following compounds has the highest fuel value?
A.
C2H6
B.
C2H4
C.
C2H2
D.
CH4
E.
C6H6

18. Calculate H° (in kJ) for reaction 3.

is -790 + 2*297 = -196 kJ. Thus B is the answer.
A.
196
B.
-196
C.
1087
D.
-1384
E.
-543

19. When we put 100-g piece of metal at 100°C into 100 g of water at 20°C, the final temperature is 60°C.
FALSE because metal and water have different specific heat, thus the heat transfer will not be equal.

20.
With reference to enthalpy changes, the term standard conditions means __________.

A.
a only
B.
b only
C.
c only
D.
a and c
E.
a and b