For A⁻ + H₂O ⇌ HA + OH⁻, Kb = Kw/Ka = (1.0 \times 10^-14 / 1.8 \times 10^-5 = 5.56 \times 10^-10)
[ M_a V_a \times n_a = M_b V_b \times n_b ] [ (0.250)(V_a)(2) = (0.100)(50.0)(1) ] [ 0.500 , V_a = 5.00 ] [ V_a = 10.0 , mL ] titrasi asam basa contoh soal
Reaction: ( H_2SO_4 + 2KOH \rightarrow K_2SO_4 + 2H_2O ) Here, ( n_a = 2 ) (H₂SO₄ gives 2 H⁺), ( n_b = 1 ) (KOH gives 1 OH⁻). For A⁻ + H₂O ⇌ HA + OH⁻, Kb = Kw/Ka = (1
0.125 M NaOH Problem 2: Finding Volume (Medium) Question: How many mL of 0.250 M H₂SO₄ are needed to neutralize 50.0 mL of 0.100 M KOH? The equivalence point is reached after adding 25
Reaction: ( HCl + NaOH \rightarrow NaCl + H_2O ) (1:1 ratio)
[ M_acid V_acid = M_base V_base ] [ (0.100 , M)(25.0 , mL) = M_base (20.0 , mL) ] [ M_base = \frac2.5020.0 = 0.125 , M ]
10.0 mL of H₂SO₄ Problem 3: Finding Molar Mass of Unknown Acid (Advanced) Question: A 0.200 g sample of an unknown monoprotic acid (HA) is titrated with 0.100 M NaOH. The equivalence point is reached after adding 25.0 mL of NaOH. What is the molar mass of the acid?