Réponse:
Bonjour,
1)m = 500mg = 0.500g
V = 5mL
Cm = m/v (formule de la concentration massique)
Donc : Cm = 0.500/5
Cm = 0.1 g/mL
2)Cm = 0.1g/mL
V = 60mL
Cm = m/V <=> m = Cm×V
Donc : m = 0.1×60
m = 6g
3) m = 1.8g
Cm = 0.1g/mL
Cm = m/V <=> V = m/Cm
Donc : V = 1.8/0.1
V = 18 mL