如何绘制此图形

Question

请您帮我画一下这个图好吗？

我将此代码用于另一个项目：

\documentclass[11pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage[francais]{babel}
\usepackage[T1]{fontenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{lmodern}
\usepackage{graphicx}
\usepackage{fullpage}
\usepackage[version=4]{mhchem}
\usepackage[left=1cm,right=2cm,top=1cm,bottom=1.5cm]{geometry}
\usepackage{pgfplots}
\usepackage{etoolbox}
\usepackage{geometry}
    
\begin{document}
    \begin{tikzpicture}
            \begin{axis}[
                scale only axis, % The height and width argument only apply to the actual axis
                height=5cm,
                width=0.9\textwidth,
                axis x line=bottom,
                axis y line = left,
                title={Évolution de la conductivité du mélange au cours du dosage},
                xlabel={Volume du nitrate d'argent ajouté en mL},
                ylabel={Conductivité en µS/cm},
                xmin=0, xmax=25,
                ymin=640, ymax=780,
                xtick={0,5,10,15,20,25},
                ytick={640,660,680,700,720,740,760,780},
                legend pos=north west,
                ymajorgrids=false,
                grid style=dashed,
                %width=\textwidth,
                minor x tick num=4,
                major tick length=0.3cm,
                minor tick length=0.15cm,
                ]
                
                \addplot[
                %color=blue,
                only marks, %seulement les poins sans trait
                %mark=square,
                %mark=halfcircle,
                mark=*,
                mark size=1pt
                ]
                coordinates {
                    (0,730)(4,710)(6,700)(10,680)
                };
                \addplot[
                %color=red,
                only marks,
                %mark=square,
                %mark=halfcircle,
                mark=*,
                mark size=1pt
                ]
                coordinates {
                    (16,680)(18,700)(20,720)
                };
            \end{axis}
        \end{tikzpicture}
\end{document}

Answer 1

再举一个 pure 的例子tikz：

\documentclass[border=3.141529]{standalone}
\usepackage[francais]{babel}
\usepackage{tikz}
\usepackage[version=4]{mhchem}

\begin{document}
    \begin{tikzpicture}
% axis
\draw[->]   (-1,0) -- 
            ( 0,0)  node[above left] {$i$} -- ++ 
            ( 5,0)  node[below left] {Vol(R)};
\draw[->]   (0,-3) -- ++ (0,4);
%
\path[draw=red, thick] 
    (0,-2) node[left]  {$i_0$}
           node[right] {\ce{Pb^++ v}} --
    (2, 0) node[above] {Pt éq $(i \approx i_R)$} -- 
    (4,-2) node[left]  {\ce{CrO_4^-- ^}};
\draw[thick, densely dotted] 
    (0,-1.9) .. controls + (2.4,2.1) and + (-2.4,2.1) .. (4,-1.9);
%
\path[draw=green, densely dashed]
    (0,-1)  node[left] {$i_1$} 
            -| (1,0) 
    node[pos=0.5, inner sep=1pt,text=gray, below right] {$\mathrm{E}_1$};
    \end{tikzpicture}
\end{document}

Answer 2

这里只有一个简单的 tikz 作为开始：

\documentclass[border=3.141cm]{standalone}

\usepackage{tikz}
\usepackage[version=4]{mhchem}


\begin{document}
    
    \begin{tikzpicture}

    \draw[->] (0,1) -- (0,5);
    \draw[->] (-1,4) -- (5,4);
    
    \node[yshift=-0.5cm,xshift=-0.5cm] at(0,5) {$i$};
    \node[xshift=-0.5cm] at(0,3) {$i_{1}$};
    \node[xshift=-0.5cm] at(0,2) {$i_{0}$};
    \node[yshift=0.5cm,xshift=-0.5cm] at(5,3) {Vol (R)};
    \node at(2.5,4.5) {$Pt\,\acute{e}q\,(i \approx i_{R})$};
    
    \draw[thick, red] (0,2) -- (2,4) -- (4,2);
    \draw[thick, rounded corners,dashed] (0,2.1) -- (2,3.9) -- (4.1,2);
    
    \node at(1,2) {\ce{Pb^++ v}};
    \node at(3,1.95) {\ce{CrO_4^-- ^}};
    
    \draw[dashed,green] (0,3) -- (1,3) --(1,4);
    \node[gray!40] at(1.25,2.75) {E\textsubscript{1}};

    \end{tikzpicture}
    
\end{document}