Answer:
pH = 8.34
Explanation:
The equilbriums of the amphoteric HCO₃⁻ (Ion of NaHCO₃) are:
H₂CO₃ ⇄ <em>HCO₃⁻</em> + H⁺ Ka1 <em>-Here, HCO₃⁻ is acting as a base-</em>
<em>HCO₃⁻</em>⇄ CO₃²⁻ + H⁺ Ka2 <em>-Here, is acting as an acid-</em>
Where Ka1 = 4.3x10⁻⁷ and Ka2 = 4.8x10⁻¹¹. As pKa = -log Ka:
pKa1 = 6.37; pKa2 = 10.32
As the pH of amphoteric salts is:
pH = (pKa1 + pKa2) / 2
<h2>pH = 8.34</h2>
Answer:
0.01504 mol/dm3
Explanation:
Calcium Hydroxide - Ca(OH)2
Hydrochloric acid - HCl
The reaction between both is given as;
2HCl + Ca(OH)2 --> CaCl2 + 2H2O
2 : 1
The relationship between the concentration and volume is given as;
CaVa / CbVb = na / nb
where a = acid (HCl) and b = base Ca(OH)2
Inserting the values;
0.04 * 18.8 / (Cb * 25) = 2 / 1
0.752 / 25Cb = 2
Cb = 0.752 / 50 = 0.01504
