Solution:
At the equivalence point, moles NaOH = moles benzoic acid
HA + NaOH ==> NaA + H2O where HA is benzoic acid
At the equivalence point, all the benzoic acid ==> sodium benzoate
A^- + H2O ==> HA + OH- (again, A^- is the benzoate anion and HA is the weak acid benzoic acid)
Kb for benzoate = 1x10^-14/4.5x10^-4 = 2.22x10^-11
Kb = 2.22x10^-11 = [HA][OH-][A^-] = (x)(x)/0.150
x^2 = 3.33x10^-12
x = 1.8x10^-6 = [OH-]
pOH = -log [OH-] = 5.74
pH = 14 - pOH = 8.26
The answer to this questions is letterB
Answer:
<h2>119.60 moles</h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
We have the final answer as
<h3>119.60 moles</h3>
Hope this helps you
Equation: M1V1 = M2V2
Where M = concentration & V = volume
Step 1: Write down what is given and what you are trying to find
Given: M1 = 6.00M, V1 = 2.49mL, and V2 = 50.0mL
Find: M2
Step 2: Plug in the values into the equation
M1V1 = M2V2
(6.00M)(2.49mL) = (M2)(50.0mL)
Step 3: Isolate the variable (Divide both sides by 50.0mL so M2 is by itself)
(6.00M)(2.49mL) / (50.0mL) = M2
Answer: M2 = 0.30M
*Don't forget sig figs & units!
How fast it changes position in time is the objects speed
