\documentclass[border=10pt]{standalone}
\usepackage{pgfplots}
\usepackage{siunitx}
\pgfplotsset{width=10cm, compat=1.9}

\begin{document}
\begin{tikzpicture}
\begin{axis}[
	title={Temperature dependence of $5H_2O$},
	xlabel={Temperature [$\unit{\degreeCelsius}$]},
	xmin=0,
	xtick={0,20,40, 60, 80,100},
	ylabel={Solubility},
	xmajorgrids=true,
	grid style=dashed, 
	legend pos=north west
]
	\addplot coordinates{
	(0,23.1)
	(10,27.1)
	(20,32)
	(30,37.8)
	(40,44.6)
	(60,61.8)
	(80,83.8)
	(100, 114)
	};
	\legend{$5H_2O$}
\end{axis}
	

\end{tikzpicture}
\end{document}