the chemical equation of nicotinic acid is C5H4NCOOH + NaOH --> C5H4NCOONa + H2O
i need to calculate the intial molar concentration of this acid, based on the ratio in which the acid and base react.
Please help i cant figure it out,
the data is
Vol. of NaOH added
0
1
2
3
4
5
10
15
20
21
22
23
24
25
26
27
28
29
30
35
40
45
50
pH
2.92
3.47
3.79
3.98
4.13
4.25
4.67
5.03
5.57
5.72
5.91
6.23
8.78
11.29
11.59
11.75
11.87
11.96
12.22
12.36
12.46
12.52
this is the data and this was given
OK. You will add the 0.1M NaOH, read the volume NaOH and the pH for each addition. I can't graph it but I will post a link that will show you how it should look. Then you will use the graph to determine the volume of NaOH used to reach the equivalence point and from there the concn of the nicotinic acid. After you know the equivalence point, you take 1/2 that volume, read the pH at the half-way point, and that will be pKa. You get Ka from pKa.
The curve will look something like this.
http://www.google.com/imgres?hl=en&client=firefox-a&hs=Szx&sa=X&tbo=d&rls=org.mozilla:en-US:official&tbm=isch&tbnid=YMzuN-RiHqx1NM:&imgrefurl=http://www.titrations.info/titration-basic-terms&docid=N4qxMJfzM-kjoM&imgurl=http://www.titrations.info/img/acetic-acid-titration-curve.png&w=368&h=284&ei=XcT0UIbvO6KE2wXszoCoDg&zoom=1&iact=hc&vpx=139&vpy=122&dur=13504&hovh=197&hovw=256&tx=149&ty=90&sig=111854003357503651221&page=2&tbnh=140&tbnw=194&start=8&ndsp=12&ved=1t:429,r:13,s:0,i:137&biw=846&bih=468
i know how to grapgh it and all i am only stuck with how to find the intial molar concentration. i believe you're telling me the step to finding the ka value.
sorry i am a little confused with this
thanks for the help i really appreciate it :D
The equivalence point is between 25 and 26 mL. The question you posted asks for Ka as well as molar concn. I told you how to do both.
okay thank you very much :)
To calculate the initial molar concentration (also known as the initial molarity or the initial concentration) of nicotinic acid (C5H4NCOOH), we need to use the balanced chemical equation and consider the stoichiometry of the reaction.
The balanced chemical equation you provided is:
C5H4NCOOH + NaOH -> C5H4NCOONa + H2O
From the balanced equation, we can see that the ratio between nicotinic acid (C5H4NCOOH) and sodium hydroxide (NaOH) is 1:1. This means that for every 1 mole of nicotinic acid, 1 mole of sodium hydroxide is required to react fully.
To calculate the molar concentration of nicotinic acid, we need to know the number of moles present initially. This can be determined using the following equation:
Moles = Molarity × Volume
However, since we are trying to find the initial concentration, we need to rearrange the equation:
Molarity = Moles / Volume
To find the initial molar concentration, we'll need the initial moles of C5H4NCOOH and the volume of the solution.
Let's say we have a solution containing 0.1 moles of nicotinic acid and a total volume of 100 mL (0.1 L). We can use these values to calculate the initial molar concentration using the equation above.
Molarity = Moles / Volume
Molarity = 0.1 moles / 0.1 L
Molarity = 1 M
Therefore, the initial molar concentration of nicotinic acid in this solution is 1 M (Molar).
Give the data clearly.
so this is the question:
you will be given a sample of nictinic acid with an unknown concentration, and it will be titrated with 0.100M NaOH. instead of measuring the volume of the basic solution required to reach the endpoint, however, you will measure the pH. Then you will graph the data you collected and use the graph to calculate the molar concentration of the nicotinic acid and its ka.