Answer
a. The autoionization of water is endothermic.
b. $[H^+]=[OH^-]=2.34*10^{-7}\text{ M}$
Work Step by Step
a. Because the reaction favors the right as we increase the temperature, the autoionization of water is endothermic.
b. $[H^+]=[OH^-]=x$ in a neutral solution.
Therefore,
$[H^+][OH^-]=5.47*10^{-14}$
$x^2=5.47*10^{-14}$
$x=2.34*10^{-7}\text{ M}$
and ...
$[H^+]=[OH^-]=2.34*10^{-7}\text{ M}$
