Question

Tolong bantu 22-25 pakai cara no spam

Answer 1

22. garam bersifat basa akan menghasilkan OH- (1,2&5)
jawabannya (E) 2 dan 5

23. M NH4Cl = 5,35/53,5 x1000/200 = 0,5 M
[H+] = √Kw/Kb x M
[H+] = √10⁻¹⁴/10⁻⁵  x 0,5 = √5x10⁻¹⁰ = √5 x10⁻⁵
pH = - log √5 x10⁻⁵ = 5 - log √5
jawabannya (B)

24. mmol HCN = 50 x10⁻³ = 5x10⁻² mmol
mmol NaOH = 50 x10⁻³ = 5x10⁻² mmol
HCN + NaOH => NaCN + H2O
[NaCN] = 5x10⁻² mmol / 100 ml = 5x10⁻⁴ M
[OH-] = √10⁻¹⁴/5x10⁻¹⁰ x 5x10⁻⁴
[OH-] = √10⁻⁸ = 10⁻⁴
pOH = - log 10⁻⁴
pOH = 4
pH = 14 - 4 = 10
jawabannya (E)

25. pH = 9+log2
pOH = 14 - (9 + log 2) = 5 - log 2
pOH = - log [OH-]
5 - log 2 = - log [OH-]
[OH-] = 2x10⁻⁵
[OH-] = √Kw/Ka x M
2x10⁻⁵ = √10⁻¹⁴/10⁻⁵ x M
4x10⁻¹⁰ = 10⁻⁹ x M
M = 0,4 M
massa CH3COONa = 0,4 mol/liter x 0,25 liter x 82 gr/mol = 8,2 gr
jawabannya (B)