Two moles of steam are heated from $200C$ and $1$MPa to $500C$ and $1$MPa. Calculate the heat input

a$.$ Using the steam tables

b$.$ Using MCPH

$A=3\mathrm{.}470,B=0\mathrm{.}725{10}^{-3}$

$C=0$

$D=0\mathrm{.}121{10}^5$

Which answer do you think is more accurate? Why?