begin{multicols}{2}
tableofcontents
end{multicols}

documentclass[12pt,article,a4paper]{scrartcl}
title{textbf{GF,CH: Themen für die mündliche Prüfung}}
date{Montag, 1.7.2019}
author{}
usepackage[german]{babel}
usepackage{multicol}

usepackage{xcolor}
definecolor{myorange}{RGB}{255,127.5,0}

usepackage{tikz}
tikzset{
  % Styling of header text is done using key/value options for TikZ nodes. See
  % section 16.4 of the PGF manual for a complete list of options that affect
  % text.
  headings/base/.style = {
    % Zap node seperation, set text width and alignment.
    outer sep = 0pt,
    % Trim off 2/3rd of an em to compensate for the inner xsep which spaces the
    % text nicely away from the left side, but causes the node to hang into the
    % right margin.
    text width = {textwidth - 0.6666em},
    align = left,
    text = black,
  },
  headings/section/.style = {
    headings/base,
    fill = myorange!50,
    font = sffamilylarge
  },
  headings/subsection/.style = {
    headings/base,
    fill = myorange!25,
    font = sffamilylarge
  }
}

newcommand{colorboxedsec}[2]{%
  tikz{node[headings/#1]{#2};}}

setkomafont{section}{colorboxedsec{section}}
setkomafont{subsection}{colorboxedsec{subsection}}




begin{document}
pagenumbering{roman}
maketitle
begin{multicols*}{2}
tableofcontents
end{multicols*}

pagenumbering{arabic}
section{Stöchiometrie}
section{Die Geometrie von Teilchen}
section{Zwischenpartikulare Kräfte}
subsection{van}
section{Reaktionsgeschwindigkeit}
section{Das chemische Gleichgewicht}
section{Beeinflussung von chemischen Gleichgewichten}
section{Fällungsreaktionen}
section{Komplexreaktionen}
section{S/B-Reaktionen}
section{Redoxreaktionen}
section{Titration}
section{Der pH-Wert}
section{Der (technische) Kalkkreislauf}
section{Chiralität}
section{E/Z-Isomerie}
section{Mesomerie und Farbe}
section{Farben}
section{Sprengstoffe}
section{Proteine}
section{Enzyme}
section{Nervengifte, Rauschgifte}

end{document}