Bonjour,
Ex3)
a) n = C x V = 1,0.10⁻¹ x 15.10⁻³ = 1,5.10⁻³ mol
b) N = n x Na = 1,5.10⁻³ x 6,02.10²³ = 9,0.10²⁰ molécules
c) m = n x M
M = 2xM(C) + 4xM(H) + 2xM(O) = 2x12 + 4x1 + 2x16 = 60 g.mol⁻¹
m = 1,5.10⁻³ x 60 = 9,0.10⁻² g
Ex 4)
a) V = n/Ci = 5,0.10⁻³/0,25 = 0,02 L = 20 mL
b) C = n/V = 5,0.10⁻³/50.10⁻³ = 0,1 mol.L⁻¹ = 1,0.10⁻¹ mol.L⁻¹
