I titrated a 250mg tablet to see if it really had 250mg of scorbutic acid (H2C6O6) a diuretic acid, in it. I took a 250mg tablet, grounded it up and found it took 35.87ml of .0505 M NaOH to neutralize it
1. How many moles of NaOH is it?
35.87ml NaOh(1L/1000ml) (.0505M/1L)= .001811435 moles
2. Write the neutralization reaction between ascorbic acid and OH−.
H2C6O6 + 2 NaOh --> 2 H20 + Na2C6H6O6
3. how many moles of ascorbic acid must have been in the 250 mg tablet?
.001811435
4. How many grams of ascorbic acid is this? How many milligrams?
176.06(molecular weight) *.001811435= .3188g or 318.8 mg
5. What % of the 250mg tablet was actually ascorbic acid?
I don't know if it's right can someone check my work? And i don't know how to do question 5.
1.
Numerically correct. You will have to get used to citing answers to the correct numnber of significant digits, depending on the given information. Here, the correct answer would be 0.001811 M.
2. The neutralization reaction is not correct. Ascorbic acid has only 1 H+, so it should read something like:
HC6H7O6+NaOH->NaC6H7O6+H2O
Which means that 1 mole of NaOH will neutralize 1 mole of ascorbic acid.
3. Despite the incorrect equation in (2) above, the answer to (3) is correct, except for the number of significant figures.
4. 318.8 (I get 319.0) is correct as well. You may have noted that 318.8mg exceeds 250 mg, which baffles me as well. So recheck the question or lab data.
5. If all fails repost to see if DrBob222 has a better clue.
I meant to say ascorbic acid is a diuretic which donates 2 H+
Ascorbic acid is a diprotic which donates 2 H+. Autocorrect is the worst
If it is diprotic, then your equation in (2) is correct, and the molar ratio NaOH/C6H7O6 would be 2, and hence the answer in 4 would be halved, ... problem solved.
Thank you! Now question 5 makes sense.
You're welcome!
Your calculations for questions 1-4 are correct.
To find the percentage of the tablet that is actually ascorbic acid, we can use the formula:
% ascorbic acid = (mass of ascorbic acid / mass of tablet) * 100
In this case, you have already determined the mass of ascorbic acid to be 318.8 mg. The mass of the tablet is given as 250 mg.
% ascorbic acid = (318.8 mg / 250 mg) * 100 = 127.5%
The result, 127.5%, seems unusually high as it is greater than 100%. There might be an error in your calculations or assumptions. Please double-check your work to ensure accuracy.