The calculated pH of the solutions are given below:
- The pH of the solution after 14.0 ml of base is added to it is calculated as 1.45.
- The pH of the solution after 19.8 ml of base is added to it is calculated as 3.0
- The pH of the solution after 20.0 ml of base is added to it is calculated as 7.
<h3>What is pH?</h3>
This is the level of acidity or alkalinity of an aqueous solution. The pH of a substances tells if its an acid, base or neutral.
HBr and NaOH while in water would dissociate and they would become H+ and OH- respectively.
Mol of HBr = Mol * Vol
= 0.200 * 20mL
= 4 mmol
A. Moles of NaOH added
= 0.2 X 14
= 2.8 mmol
Moles of H+ that did not react
= 4 - 2.8
= 1.2 mmol
1.2/1000 = 0.0012 moles
Total volume = 20 + 14
= 34 mL to litres
= 0.034 L
Molarity of H+ = 0.0012 / 0.034L
= 0.035 M
-log[0.035] = 1.45
The pH of the solution is 1.45
B. NaOH added = 19.8 * 0.2 =
3.96 mmoles
The unreacted solution
= 4.0 - 3.96
= 0.04 mmol
0.04/1000 = 0.00004 moles
Total volume = 20 + 19.8
= 39.8mL
Converted to litres = 0.0398L
Molarity = 0.00004 / 0.0398L
= 0.001
-log(0.001) = 3.0
The ph Is therefore 3.0
C. Moles of NaOH added = 0.2*20mL = 4mmol
All the H+ are going to be consumed here. This would result into a neutral solution pH = 7
<u>Complete question:</u>
20.0 mL sample of 0.200 M HBr solution is titrated with 0.200 M NaOH solution. Calculate the PH of the solution after the following volumes of base have been added.
A. 14.0 mL
B. 19.8 mL
C. 20.0 mL
Read more on pH here; brainly.com/question/22390063
The anoles that changed were the descendants of the anoles studied four years earlier by Losos.
<h3>What is natural selection?</h3>
Natural selection is a term that refers to the evolutionary process that is based on the principle that establishes the survival of the fittest or the preponderance of the law of the strongest in a natural environment without external intervention.
In natural selection, the least fit or weakest individuals perish and their traits are not transmitted to the following generations by not reproducing.
According to the above, it can be inferred that the traits of the weak or less fit organisms studied four years earlier were not transmitted to the following generations, so the organisms studied by Losos four years later are not the same, but the offspring of The originals.
Learn more about natural selection in: brainly.com/question/9830102
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Answer:
here's your answer - the angle of elevation