What is the ph of a solution (500 ml, 3.40 mm hoac) in which 50 ml of 1.00 m hcl is added? what percentage of the hoac is dissociated?

a) pH = 1.0414

b) ∝ = 0.156 %

Explanation:

∴ n HCL = (0.05L)*( 1 mol/L) = 0.05 mol

       HCl → H3O+  +  Cl-

ni     0.05     -              -

nf      -         0.05       0.05

weak acid:

∴ mol CH3COOH = (0.500L)*(3.40 E-3 mol/L ) = 1.7 E-3 mol

    CH3COOH ↔ CH3COO- +   H3O+

ni     1.7 E-3                 -                0.05

nf    1.7 E-3 - X            X             0.05 + X ≅ 0.05

∴ Ka = 1.75 E- 5 = ([ H3O+]*[CH3COO-])/[CH3COOH]

by lechatelier the reaction shifts to the left, then the moles of H3O+ in the weak acid is practically equal to 0.05 moles of the strong acid.

⇒  [H3O+] = 0.05 mol / 0.55 L = 0.0909 M

⇒ pH = - Log ( 0.0909 )

⇒ pH = 1.0414

replacing en Ka:

⇒ 1.75 E-5 = ((0.05+X)/0.55)*(X/0.55)) / ((1.7 E-3-X)/0.55)

⇒ 0.55X² + 0.3025X - 8.99 E-9 = 0

⇒ X = 4.8424 E-6 M

⇒ [H3O+] = 0.05mol/0.55L + 4.8424 E-6 = 0.0909 M

the assumption has been demonstrated

∴ percentage of tha CH3COOH is dissociated (∝):

⇒ ∝ = ( [CH3COO-] / ([CH3COO-] + [CH3COOH]) ) * 100

∴ [CH3COO-] = X = 4.824 E-6 M

∴ [CH3COOH] = 1.7 E-3 mol/0.55 L - 4.824 E-6 = 3.086 E-3 M

⇒ ∝ = ((4.824 E-6) / (3.086 E-3 + 4.824 E-6 )) * 100

⇒ ∝ = 0.156 %

answer: the rate of diffusion increases with increase in temperature.

increase in temperature, increases the molecular/particles speed (kinetic energy. diffusion means movement of particles through the material.

generally, the heavier the particle the more it interacts with the environment and more the temperature matters. so higher temperature results in higher diffusion.