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
Matter 15. This new pH out-of 0.1 Meters service off cyanic acid (HCNO) try dos.34. Determine the ionization constant of your own acidic as well as degree of ionization in the solution. HCNO \(\rightleftharpoons\) H + + CNO – pH = 2.34 setting – journal [H + ] = 2.34 or journal [H + ] = – dos.34 = step three.86 otherwise [H + ] = Antilog 3.86 = cuatro.57 x 10 -step three Yards [CNO – ] = [H + ] = 4.57 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 dos.thirty-six x ten -5 = 944 x ten -7 pOH = – journal (nine.forty-two x 10 -eight ) = 7 – 0.9750 = 6.03 pH = fourteen – pOH = 14 – 6.03 Jacksonville escort service = 7.97
Question 17. What is the minimum 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 latest solubility harmony on the over loaded solution is AgCl (s) \(\rightleftharpoons\) Ag + (aq) + Cl – (aq) New solubility off AgCl are 1
- Suggest the differences ranging from ionic product and you can solubility equipment.
- The latest solubllity regarding AgCI in the water in the 298 K was 1.06 x 10 -5 mole for each litre. Calculate was solubility unit at that heat.
The new solubility equilibrium from the over loaded solution is AgCl (s) \(\rightleftharpoons\) Ag + (aq) + Cl – (aq) The new solubility from AgCl is actually step 1
- It’s appropriate to types of alternatives.
- Its well worth changes for the improvement in swindle centration of one’s ions.
The solubility harmony on saturated solution is AgCl (s) \(\rightleftharpoons\) Ag + (aq) + Cl – (aq) This new solubility out of AgCl is actually 1
- It is appropriate towards saturated solutions.
- It’s got a particular really worth to own an electrolyte within a steady temperatures.
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: