Question

Need help with number three please

salt Find the pH of a buffer solution containing of 1.5M sodium acetate and 0.9M acetic acid. The K. of acetic acid is 1.8 x 105. acid pH=pka + log I salt) pH =-103(18410 9) +10g -(-4.74)+(. 2a) =14.96 2. Find the pH of 100.0 mL of the buffer from exercise 1 after the addition of 0.030 mol of gascous hydrochloric acid. Assume no volume change. Find the pH of 200.0 mL buffer from exercise 1 after the addition of 150.0 mL of 0.020M NaOH.

Answer 1

Question 2.

pH = pKa + Log{[CH3COONa - HCl]/[CH3COOH + HCl]}

Moles of CH3COONa = (100/1000) L * 1.5 mol/L = 0.15 mol

Moles of CH3COOH = (100/1000) L * 0.9 mol/L = 0.09 mol

Now, pH = 4.74 + Log{(0.15 - 0.03)/(0.09 + 0.03)}

Therefore, pH = 4.74

Question 3.

pH = pKa + Log{[CH3COONa + NaOH]/[CH3COOH - NaOH]}

Moles of CH3COONa = (200/1000) L * 1.5 mol/L = 0.3 mol

Moles of CH3COOH = (200/1000) L * 0.9 mol/L = 0.18 mol

Moles of NaOH = (150/1000) L * 0.02 mol/L = 0.003 mol

Now, pH = 4.74 + Log{(0.3 + 0.003)/(0.18 - 0.003)}

Therefore, pH = 4.97