A total of 31.3 ml of 0.15 N NaOH was required to reach a phenolphthalein endpoint in titrating 6.00 g vinegar. Calculate the number of equivalents of acetic acid in vinegar. Calculate the number of grams of acetic acid present in the vinegar. Calculate the percent by weight of acetic acid in vinegar.
Liters x normality x equivalent weight = grams. I prefer to use
mL x N x milliequivalent weight = grams.
31.3 mL x 0.15 N x 0.060 = 0.282 g acetic acid
% w/w acetic acid = (0.282 g/6.00)*100 = ?% acetic acid in the sample.
The number of equivalents is L x N = 0.0313 x 0.15 = ?
When I was in school we worked ALL of our quant chem problems with milliquivalents and not with molarity. Normality is a disappearing word in chemistry I'm sorry to say.
Why did the vinegar go to school? To acetic-ate!
Alright, let's get down to business. To calculate the number of equivalents of acetic acid in the vinegar, we need to determine the number of moles of NaOH used in the titration.
First, let's convert the volume of NaOH used in liters:
31.3 ml = 31.3/1000 L = 0.0313 L
Now, let's calculate the number of moles of NaOH:
moles of NaOH = concentration of NaOH x volume of NaOH
= 0.15 N x 0.0313 L
= 0.00469 moles
Since acetic acid reacts with NaOH in a 1:1 ratio, the number of equivalents of acetic acid is also 0.00469.
Next, to calculate the number of grams of acetic acid present in the vinegar, we use the molar mass of acetic acid, which is 60.05 g/mol.
grams of acetic acid = moles of acetic acid x molar mass of acetic acid
= 0.00469 moles x 60.05 g/mol
= 0.2809 g
Finally, to calculate the percent by weight of acetic acid in vinegar, we use the formula:
percent by weight = (grams of acetic acid / grams of vinegar) x 100
grams of vinegar = 6.00 g
percent by weight = (0.2809 g / 6.00 g) x 100
= 4.68%
So, the number of equivalents of acetic acid in vinegar is 0.00469, the number of grams of acetic acid present in the vinegar is 0.2809 g, and the percent by weight of acetic acid in vinegar is approximately 4.68%.
To calculate the number of equivalents of acetic acid in vinegar, we can use the equation:
Number of equivalents = Volume of NaOH (in liters) * Normality of NaOH
First, let's convert the volume of NaOH from milliliters to liters:
31.3 ml = 31.3/1000 liters = 0.0313 liters
Now we can calculate the number of equivalents:
Number of equivalents = 0.0313 liters * 0.15 N = 0.004695 equivalents
To calculate the number of grams of acetic acid present in the vinegar, we can use the molecular weight of acetic acid. The molecular weight of acetic acid is approximately 60.05 g/mol.
Number of grams = Number of equivalents * Molecular weight of acetic acid
Number of grams = 0.004695 equivalents * 60.05 g/mol = 0.2813 grams
Finally, to calculate the percent by weight of acetic acid in vinegar, we divide the mass of acetic acid by the mass of vinegar and multiply by 100:
Percent by weight = (Mass of acetic acid / Mass of vinegar) * 100
Percent by weight = (0.2813 grams / 6.00 grams) * 100 = 4.69%
Therefore, there are approximately 0.004695 equivalents of acetic acid in vinegar, which is equivalent to 0.2813 grams. The percent by weight of acetic acid in vinegar is approximately 4.69%.
To calculate the number of equivalents of acetic acid in vinegar, we need to determine the moles of NaOH used in the titration. From the given information, we can calculate the moles of NaOH using the formula:
moles of NaOH = (volume of NaOH (in liters)) * (molarity of NaOH)
First, let's convert the volume of NaOH from milliliters to liters:
volume of NaOH = 31.3 ml = 31.3/1000 L = 0.0313 L
Now we can calculate the moles of NaOH:
moles of NaOH = (0.0313 L) * (0.15 N) = 0.00469 moles
Since acetic acid (C2H4O2) reacts with NaOH in a 1:1 stoichiometric ratio, we can conclude that the number of moles of acetic acid in vinegar is also 0.00469 moles.
To calculate the number of grams of acetic acid present in the vinegar, we need to use the molar mass of acetic acid, which is 60.05 g/mol:
grams of acetic acid = (moles of acetic acid) * (molar mass of acetic acid)
grams of acetic acid = (0.00469 moles) * (60.05 g/mol) = 0.281 g
Finally, to calculate the percent by weight of acetic acid in vinegar, we need to divide the mass of acetic acid by the mass of the vinegar sample (6.00 g) and multiply by 100:
percent by weight = (grams of acetic acid / mass of vinegar) * 100%
percent by weight = (0.281 g / 6.00 g) * 100% ≈ 4.68%
Therefore, the number of equivalents of acetic acid in vinegar is 0.00469 eq, the number of grams of acetic acid present in the vinegar is 0.281 g, and the percent by weight of acetic acid in vinegar is approximately 4.68%.