Question

Master kimia mana nih?

Answer 1

P = 152 cmHg = 2 atm
T = 27⁰C = 300⁰K


n HCl = (P x V) / (R x T)
n HCl = (2 x 0,012) / (0,08 x 300)
n HCl = 0,001 mol

n NH₃ = (P x V) / (R x T)
n NH₃ = (2 x 0,06) / (0,08 x 300)
n NH₃ = 0,005 mol

Persamaan reaksi :
       HCl  +  NH₃   →    NH₄Cl
a   0,001     0,005
r    0,001     0,001
__________________________
s       -         0,004        0,001

Pakai rumus larutan penyangga
[OH⁻] = Kb • mol sisa basa/mol garam
[OH⁻] = 10⁻⁵ •  0,004/0,001
[OH⁻] = 4 x 10⁻⁵


Fe(OH)₂ ⇆ Fe²⁺ + 2OH⁻
Ksp Fe(OH)₂ = [Fe²⁺] [OH⁻]²
10⁻¹⁶ =  [Fe²⁺] [4 x 10⁻⁵]²
10⁻¹⁶ =  [Fe²⁺] [1,6 x 10⁻⁹]
[Fe²⁺] = 10⁻¹⁶ / 1,6 x 10⁻⁹
[Fe²⁺] = 6,25 x 10⁻⁸