import matplotlib.pyplot as plt 
import numpy as np

def cinetique(N,tf,Ca0,k):
    Ca=[Ca0]
    t=[0]
    h=tf/N
    for i in range (N):
        t.append(t[i]+h)
        Ca.append(Ca[i]*(1-k*h))
    x=np.linspace(0,5,100)
    y=np.exp(-x)
    plt.plot(t,Ca)
    plt.plot(x,y)
    plt.show()