em 126 Exam 2 March 5 2018 1C 1S pointCalculate the pt of 0

em 126 Exam 2 March 5, 2018 1C 1S point)Calculate the pt of 0 10 M NaoCI solution K, hypochlorous acid 30x 10) Reaction: pH a 2A) (3 points) Calculate Q and the direction of equilibrium for the Haber process at 500°C, if initial partial pressures rae PIN,)-155 atm, P(H,)-18 atm, and P(NH,) -5.1 atm. K, 1.5x10 N,(g)+ 3H,(8) 2NH,(E) Q: 2B) (a point) Direction of the equilibrium ( circle one): to the left to the right

Solution

1C)

NaOCl = 0.10M

NaOCl------------------ Na+ + OCl-

OCl- +   H2O -------------------- HClO + OH-

0.10                                   0           0

-x                                     +x          +x

0.10-x                               +x          +x

Ka= 3.0x10^-8

ka x Kb= Kw                 where Kw= ioinc product of water = 1.0x10^-14

Kb= Kw/Ka = 1.0x10^-14/3.0x10^-8 = 3.33x10-7

Kb= 3.33x10^-7

kb= [HClO][OH-]/[ClO-]

3.33x10^-7 = x*x/(0.10--x)

for solving the equation

x=0.00018M

[OH-] = 0.00018M

-log[OH-] = -log[0.00018]

POH= 3.74

PH + POH= 14

PH= 14 - POH

PH= 14-3.74

PH= 10.26

2a)

        N2(g)   + 3 H2(g) --------------------- 2 NH3(g)

PN2= 155 atm     PH2= 18 atm                 PNH3 =5,1atm                      Kp= 1,5x10^-5

Q= P^2NH3/PN2 xP^3H2

Q= (5.1)^2/(155)x(18)^3

Q= 2.877 x10^-5

Q > KP

2b)

Q > Kp

so the reaction proceeds to the left side. ,i,e back word reaction is proceed.