Homework Answers

Answer #1

MW of NaC7H5 O2 -144.11g/mol wt = 10.06 g

mol of NaC7H5O2 = 10.06 /144.11=0.0698mol

con of sodium benzoate= 0.0698 / 2.5 = 0.0279M

benzoic acid = 0.360M

ka= 6.3x10^-5 pKa = -log Ka = -log 6.3 x10^-5 = 5- 0.79934=4.20066

pH = pKa + log[salt] / [acid] = 4.20066 +log [0.0279]/ [0.36]=4.20066+log 0.0775=4.20066- 1.11069

pH= 3.08997

when HCl is added

HC7H5O2 + H+   --------> C7H5O2-

0.9 mol         0               0.0698 mol initial

0.9 + 0.0125mol           0.0698 - 0.0125 at equlibirium

pH = pKa + log [salt] / [acid ]

pH = 4.20066+ log [0.0573]/ [0.9125]

pH = 4.20066+log 0.06279452

pH = 4.20066 -1.20207= 2.99859

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Find the result of operating with d^2 /d x^2 + d^2 /d y^2 + d^2 /d...
Find the result of operating with d^2 /d x^2 + d^2 /d y^2 + d^2 /d z^2 on the function x^2 + y^2 + z^2 .
President u d d u u d a a d u d d Table above shows...
President u d d u u d a a d u d d Table above shows 12 students took a survey for for President Obama election decision letters means the following   "A" = Approve "D" = Disapprove "U" = Undecided Is it reasonable to assume that the 12 people that responded are a representative sample of all adults aged 21 or more years living in the United States at that time? Clearly, but briefly, state why or why not. Regardless...
Show that if a and d are positive integers, then (-a) div d= -a div d...
Show that if a and d are positive integers, then (-a) div d= -a div d if and only if d divides a.
Please reduce this boolean function to its minimal form with clear steps (C*~D*B)+(C*~D*A)+(~B*D*C)+(~B*D*A)+(~A*~B*~D)+(~A*B*D)
Please reduce this boolean function to its minimal form with clear steps (C*~D*B)+(C*~D*A)+(~B*D*C)+(~B*D*A)+(~A*~B*~D)+(~A*B*D)
Given d[D]/dt = k1[A]2 - k2[D] - k3[B][D] = 0 Determine an expression for the concentration...
Given d[D]/dt = k1[A]2 - k2[D] - k3[B][D] = 0 Determine an expression for the concentration of [D]
Evaluate ∬ D ( x + y ) d A where D is the region defined...
Evaluate ∬ D ( x + y ) d A where D is the region defined by the parabola y = -x2 + 4, y=0(x-axis) and x=0(y-axis)
if f: D - R be continuous, and D is close, then F(D) is closed. prove...
if f: D - R be continuous, and D is close, then F(D) is closed. prove or give counterexample
Let D={0,1,2,3,4,5,6,7,8,9} be the set of digits. Let P(D) be the power set of D ,...
Let D={0,1,2,3,4,5,6,7,8,9} be the set of digits. Let P(D) be the power set of D , i.e. the set of all subsets of D . How many elements are there in P(D) ? Prove it! Which number is greater: the number of different subsets of D which contain the digit 7 or the number of different subsets of D which do not contain the digit 7? Explain why! Which number is greater: the number of different subsets of D which...
Let D ⊆ R, a ∈ D, let f, g : D −→ R be continuous...
Let D ⊆ R, a ∈ D, let f, g : D −→ R be continuous functions. If limx→a f(x) = f(a) and limx→a g(x) = g(a) with f(a) < g(a), then there exists δ > 0 such that x ∈ D, 0 < |x − a| < δ =⇒ f(x) < g(x).
Show 3 | (a − b)(b − c)(c − d)(a − c)(b − d)(a − d)...
Show 3 | (a − b)(b − c)(c − d)(a − c)(b − d)(a − d) knowing a,b,c,d are arbitrary integers that are positive.