Question

1) Determine the Kb for CN at 25°C The K, for HCN is 49. 10-10 A) 3.7 10-7 B) 23 , 10-9 14 x 10-5 D) 49 10-14 E) 20 - 10-5 2 ) 2) Calculate the solubility (in g/L) of calcium fluoride in water at 25°C if the Ksp for Ca F2 is 1.52 10-10 A) 96 10-4 gł B ) 26 x 10-2 g/L. C) 4.1 10-2 g/L D) 3.3 * 10-2 g/l 3) in the reaction C&HCl(aq) + H20(1) - C4H9OH(aq) + HCl(aq) the concentration of the reactant changes from 0.0562 M to 0.0431 M in 85 sec. What is the average rate of decomposition over this interval? A) 1.54 x 10-4 moles B) 1.54 x 10-4 moles/s C)1.54 10-4 M/s D) 0.0154 M E) 0.0154 M/S

Answer 1

| Kath = kw - 10x1514 kcha lookoll leoglaly. 4. 9x1&lo KG = 2.0x105 Ca F2 S) Cath aa) + 2 arl +28 - S (25)uss

3 1.5x100 - us 5=38 1.5x160 = 0 000 334, at 4 molla Solubility in gl = Sxmoper mass . 0.60 339306) 78.7 9.00 20.02615 9/L= 2.6x162 gl. Answer ® = 2.68/02 - (3 Avarse sak - Anal Inthral canc- final cons = 0.0562 -0,0431 m. 0:013) m/s = 0.000 154 m/s S = 154X664m/s Алаек Answer