Answer:
B. It is important that people are not harmed for the sake of science.
Explanation:
Ethical principles stress the need to do good and cause no harm.A researcher is therefore required to;
- obtain an informed consent from the participants
- minimize or eliminate risk of harm to participants
- protect the anonymity and confidentiality of participants
- Apply no deceptive techniques
- allow the right to withdraw from the study by a participant
C or a one of those hope it helps !!!!
<u>Given information:</u>
Concentration of NaF = 0.10 M
Ka of HF = 6.8*10⁻⁴
<u>To determine:</u>
pH of 0.1 M NaF
<u>Explanation:</u>
NaF (aq) ↔ Na+ (aq) + F-(aq)
[Na+] = [F-] = 0.10 M
F- will then react with water in the solution as follows:
F- + H2O ↔ HF + OH-
Kb = [OH-][HF]/[F-]
Kw/Ka = [OH-][HF]/[F-]
At equilibrium: [OH-]=[HF] = x and [F-] = 0.1 - x
10⁻¹⁴/6.8*10⁻⁴ = x²/0.1-x
x = [OH-] = 1.21*10⁻⁶ M
pOH = -log[OH-] = -log[1.21*10⁻⁶] = 5.92
pH = 14 - pOH = 14-5.92 = 8.08
Ans: (b)
pH of 0.10 M NaF is 8.08
Answer:
There are many errors possible while titrating the acid of an unknown concentration with a base like NaOH.
Main error that leads to the error in results is misreading of the end point volume .
End point is when the reaction between the analyte and solution of known concentration has stopped .
Sometimes Burette is not straight enough to read the volume of the end point. One way to misread the volume of burette is by looking at the burette volume at an angle .
From above , volume seems to be higher. Indicators are used to indicate the color change of the reaction. In Acid-Base titrations , indicators first lighten up then changes its color.
So, error may have occurred in wrongly judging of the end point by color change of the indicator .
It is a compound because a compound is two or more different elements chemically combined.
