The acidic substance in vinegar is acetic acid, HC2H3O2. When 4.00 g of a certain vinegar sample was titrated with 0.200 M NaOH,
1 answer:
You might be interested in
The pH of the solution in which one normal adult dose aspirin is dissolved is : 2.7
Given data :
mass of aspirin = 640 mg = 0.640 g
volume of water = 10 ounces = 0.295735 L
molar mass of aspirin = 180.16 g/mol
moles of aspirin = mass / molar mass = 0.00355 mol
<h3>Determine the pH of the solution </h3>First step : <u>calculate the concentration of aspirin</u>
= moles of Aspirin / volume of water
= 0.00355 / 0.295735
= 0.012 M
Given that pKa of Aspirin = 3.5
pKa = -logKa
therefore ; Ka = =
From the Ice table
=
=
given that the value of Ka is small we will ignore -x
x² =
x =
Therefore
[ H⁺ ] =
given that
pH = - Log [ H⁺ ]
= - ( -3 + log 1.948 )
= 2.71 ≈ 2.7
Hence we can conclude that The pH of the solution in which one normal adult dose aspirin is dissolved is : 2.7
Learn more about Aspirin : brainly.com/question/2070753
Answer:
a)
b) entropy of the sistem equal to a), entropy of the universe grater than a).
Explanation:
a) The change of entropy for a reversible process:
The energy balance:
If the process is isothermical the U doesn't change:
The work:
If it is an ideal gas:
Solving:
Replacing:
Given that it's a compression: V2<V1 and ln(V2/V1)<0. So:
b) The entropy change of the sistem will be equal to the calculated in a), but the change of entropy of the universe will be 0 in a) (reversible process) and in b) has to be positive given that it is an irreversible process.