\tikz{
\draw[thick](0,3)--(0,0)--(3,0);
\draw[semithick,densely dashed](0,0.7)--(3,2.5);
\draw[thick](0.6,1.06)--(3,2.5);
\draw(-0.3,1.6) node[rotate=90]{\scriptsize$\ln K$};
\draw(1.8,-0.4) node[right]{\scriptsize$\dfrac{1}{\ T\ }/{\rm K}^{-1}$};
}
\tikz{
\draw[thick](0,3)--(0,0)--(3,0);
\draw[semithick,densely dashed](0,0.7)--(3,2.5);
\draw[thick](0.6,1.06)--(3,2.5);
\draw(-0.3,1.6) node[rotate=90]{\scriptsize$\ln K$};
\draw(1.8,-0.4) node[right]{\scriptsize$\dfrac{1}{\ T\ }/{\rm K}^{-1}$};
}