Question 13. 76. Calculate the concentration of hydrogen ion in it. Answer: pH = – logten [H3O + ] = – log10 = – pH = – 3.76 = \(\overline
Question 14. The ionisation constant of HF, HCOOH, HCN at 298 K are 6.8 x 10 -4 , 1.8 x 10 -4 and 4.8 x 10 -9 respectively. Calculate the ionisation constant of the corresponding conjugate base. Answer: 1. HF, conjugate base is F Kb = Kw/Ka = \(\frac<1>><6.8>>\) = l.47 x 10 -eleven = l.5 x 10 -11
Concern fifteen. Brand new pH from 0.step 1 M services from cyanic acidic (HCNO) is actually dos.34. Determine the new ionization ongoing of your acid and its level of ionization from the solution. HCNO \(\rightleftharpoons\) H + + CNO – pH = dos.34 setting – journal [H + ] = dos.34 or record [H + ] = – 2.34 = step three.86 otherwise [H + ] = Antilog step three.86 = 4.57 x 10 -step 3 Yards [CNO – ] = [H + ] = cuatro.57 x ten -step 3 M
Question 16. The Ionization constant of nitrous acid is 4.5 x 10 -4 . Calculate the pH of 0.04 M sodium nitrite solution and also its degree of hydrolysis. Answer: Sodium mtrite is a salt of weak acid, strong base. Hence, Kh = 2.22 x 10-11 Kw/Kb = 10 -14 /(4.5x 10 -4 )
[OH – ] = ch = 0.04 x 2.thirty six x 10 -5 = 944 x ten -7 pOH = – log (9.forty-two x ten -eight ) = 7 – 0.9750 = 6.03 pH = fourteen – pOH = 14 – 6.03 = seven.97
Question 17. What is the minimum https://datingranking.net/escort-directory/meridian/ volume of water required to dissolve 1 g of calcium sulphate at 298K. For calcium sulphate, Ksp = 9.1 x 10 -6 . Answer: CaSO4(s) Ca 2 (aq) + SO 2- 4(aq) If ‘s’ is the solubility of CaSO4 in moles L – , then Ksp = [Ca 2+ ] x [SO4 2- ] = s 2 or
= 3.02 x 10 -3 x 136gL -1 = 0.411 gL -1 (Molar mass of CaSO4 = 136 g mol -1 ) Thus, for dissolving 0.441 g, water required = I L For dissolving 1g, water required = \(\frac < 1>< 0.411>\)L = 2.43L
The solubility balance from the soaked option would be AgCl (s) \(\rightleftharpoons\) Ag + (aq) + Cl – (aq) The latest solubility regarding AgCl was 1
- Suggest the difference ranging from ionic tool and you can solubility equipment.
- The solubllity away from AgCI within the water from the 298 K is step 1.06 x 10 -5 mole for each litre. Determine try solubility tool at that heat.
The newest solubility harmony regarding soaked option would be AgCl (s) \(\rightleftharpoons\) Ag + (aq) + Cl – (aq) The newest solubility out-of AgCl is 1
- It is relevant to all form of choice.
- The well worth alter for the change in scam centration of one’s ions.
The latest solubility balance regarding the saturated option would be AgCl (s) \(\rightleftharpoons\) Ag + (aq) + Cl – (aq) This new solubility out-of AgCl was 1
- It’s relevant to the over loaded solutions.
- It offers one well worth for a keen electrolyte in the a steady heat.
2. 06 x 10 -5 mole per litre. [Ag + (aq)] = 1.06 x 10 -5 mol L -1 [Cl – (aq)] = 1.06 x 10 -5 mol L -1 Ksp = [Ag + (aq)] [Cl – (aq)] = (1.06 x 10 -5 mol L -1 ) x (1.06 x 10 -5 mol L -1 ) = 1.12 x 10 -2 moI 2 L -2
Question 19. The value of K of two sparingly soluble salts Ni(OH)2 and AgCN are 2.0 x 10 -15 and 6 x 10 -17 respectively. Which salt is more soluble? Explain. Answer: