We did a titration lab, and one of the post-lab questions says: "the manufacturer of the vinegar used in this experiment claims that the vinegar contains 5% acetic acid by weight. Use your results and a density of 1g/mL to determine if this claim is true or false.
So the concentration of acetic acid I found in my experiment was 0.8655 M, and i used the molar mass of acetic acid to find that the acetic acid would be 51.98g/mL.
I known that I need to have the mass of the acetic acid and the mass of the vinegar solution to find the perecnt I'll need, but how do I go from the 51.98 g/mL to just g and how would I find the g of the vinegar solution? (and where does the density come in??)
Thank you in advance!
To determine if the manufacturer's claim about the vinegar's acetic acid content is true or false, you need to calculate the acetic acid mass in the vinegar solution.
First, let's discuss the role of density in this calculation. Density is the ratio of mass to volume and is given in the question as 1g/mL for vinegar. This means that 1 mL of vinegar weighs 1 gram. Since density is expressed in terms of volume, you can relate it to the concentration of acetic acid, which is given in moles per liter (M).
Now, let's move on to calculating the acetic acid mass in grams. You have the molar concentration of acetic acid in your experiment, which is 0.8655 M. To convert this to grams per milliliter (g/mL), you have correctly used the molar mass of acetic acid to find that it is 51.98 g/mL. However, this value represents the mass of 1 mole of acetic acid occupying a volume of 1 milliliter.
To convert 51.98 g/mL to just grams (g), you need to multiply it by the volume of acetic acid in milliliters that you used in the titration. Let's say you used V milliliters of acetic acid during the experiment. Multiply 51.98 g/mL by V mL to obtain the mass of acetic acid used.
Next, you need to determine the mass of the vinegar solution used in the experiment. This can be done by weighing the volume of vinegar solution used in grams, taking into account the density of vinegar (1g/mL). Let's say you used V' milliliters of vinegar solution. The mass of the vinegar solution used would be V' grams.
Finally, to calculate the percentage of acetic acid in the vinegar solution, divide the mass of the acetic acid by the mass of the vinegar solution used, and then multiply by 100. The formula for this calculation is:
% Acetic acid = (mass of acetic acid / mass of vinegar solution) x 100
To summarize the steps:
1. Convert 51.98 g/mL to grams by multiplying it by the volume of acetic acid used (V mL).
2. Weigh the volume of vinegar solution used (V' mL) to determine its mass in grams.
3. Calculate the percentage of acetic acid in the vinegar solution using the formula above.
By calculating the percentage of acetic acid in the vinegar solution, you can compare it to the claimed value of 5% by weight and determine if the manufacturer's claim is true or false.