How are the concentrations of hydrogen ions and hydroxide ions related in an aqueous solution? a
Their sum equals 1.0x10^-14
b
Their sum equals 14.
c
Their values are always equal.
d
Their product equals 1.0x10^-14

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"

the answer is:  

line graphs show patterns in data with variables that change over time; whereas, circle graphs show data as parts out of a whole (such as out of 100%).