Answer:
8.54
Explanation:
At equivalence point :
42.2 X 0.052 = Vol. NaOH X 0.0372
Vol of NaOH = 2.1944/0.0372 = 58.99 ml
So volume of NaOH recquired to reach equivalence point = 58.99 ml
Number of miliimoles of CH3COOH = molarity X volume in ml = 42.2 X 0.052 = 2.1944 millimoles
Number of millimoles of NaOH = 58.99 X 0.0372 = 2.1944
Now CH₃COOH and NaOH reacts to give CH₃COONa according to the reaction :
CH₃COOH + NaOH ------> CH₃COONa + H₂O
1 mole of CH₃COOH reacts with 1 mole of NaOH to give 1 mole of CH₃COONa
So 2.1944 millimoles of CH₃COOH will react with 2.1944 millimoles of NaOH to give 2.1944 millimoles of CH₃COONa
So all the acid (CH₃COOH) and base (NaOH) has been converted into salt (CH₃COONa) so there is no acid or base left.
Now molarity of CH₃COONa = number of millimoles of CH₃COONa/total volume in ml = 2.1944/(58.99 + 42.2) = 2.1944/101.19 = 0.02169 M
So using the hydrolysis equation :
pH = 1/2 [ pKw + pKa + log c ]
Ka for acetic acid = 1.75 X 10⁻⁵
so pKa = -log (1.75 X 10⁻⁵) = 4.74
Kw = 10⁻¹⁴
so pKw = -log 10⁻¹⁴ = 14
c = 0.02169
so log c = log 0.02169 = -1.66
putting the values....
pH = 1/2 [14 + 4.74 - 1.66 ]
pH = 1/2 [ 17.08] = 8.54
Answer:
energy is stored in the chemical bonds in molecules
Explanation:
#6).
Every 1,000 mL makes 1 L
How many 1,000mL are there in 2,800 mL ?
That's division.
(2,800 mL) / (1,000 mL) = <em>2.8 L</em>
#7).
The 'perimeter' means the 'distance all the way around'.
You have to know that both sides of a rectangle are the same length,
and also the top and bottom are the same length.
So the perimeter of this rectangle is
(2 yd) + (4.5 yd) + (2.yd) + (4.5 yd) = 13 yd .
Oops. The problem wants to know the perimeter in feet.
So you have to know that each yard is the same as 3 feet.
In order to find the number of feet in 13 yards, you have to
take 3 feet 13 <em><u>times</u></em> .
(3 feet) times (13) = <em>39 feet .</em>
#8).
For this one, you have to know that every 36 inches makes 1 yard.
How many 36 inches are there in 48 inches ?
That's division.
(48 inches) / (36inches) = <em>1 and 1/2 yards</em> .
#9).
For this problem, you have to know how to handle a mixed number,
and you also have to know that there are 16 ounces in 1 pound.
Add up the fruit:
(3-1/2 pounds) + (4 pounds) + 2 pounds) = <em><u>9-1/2 pounds</u></em>
Now, remember that each pound is the same as 16 ounces. So if you
want to find the number of ounces in 9-1/2 pounds, you have to take
16 ounces 9-1/2 times .
(16 ounces) times (9-1/2) = <em>152 ounces</em>.
___________________________________
#10).
This one is just adding up some numbers. But after you finish doing that, you have to know that 1,000 meters is called '1 kilometer' .
Add up the distances that Omar ran:
(1,000 meters) + (1,625 meters) + (1,500 meters) = <em><u>4,125 meters</u></em>
The problem wants to know how many kilometers this is, so you have to figure out how many '1,000 meters' fit into 4,125 meters.
That's division.
(4,125 meters) / (1,000 meters) = <em>4.125 kilometers</em>
Explanation:
attribute of a person that often cannot be measured directly but can be assessed using numbers of indicators or manifest variables
