A student dissolves a .726 g aspirin tablet in water and titrates the solution with .272 M NaOH are required to reach the equivalence point. Calculate the percentage of acetylsaliclic acid in the tablet.
I am not really sure where to start with this. I unfamiliar with problems like these.
I use this most often but it's a couple of equations put together.
mL x M x (molar mass/1000) = grams
You don't list mL in the problem and you must have that. M - 0.272. Molar mass acetylsalicyclic acid you can look up. Calculate grams.
Then % ASA = (grams ASA/0.726 sample)*100 = ?
No problem! I can help you step-by-step to solve this problem.
Step 1: Calculate the moles of NaOH used
To do this, we need to use the formula:
moles = concentration × volume (in liters)
Given: concentration of NaOH = 0.272 M
volume of NaOH used = 22.0 mL = 0.0220 L (since 1 mL = 0.001 L)
moles of NaOH = 0.272 M × 0.0220 L = 0.005984 moles
Step 2: Determine the balanced chemical equation
The balanced chemical equation of the titration reaction is:
Aspirin (acetylsalicylic acid) + NaOH → Sodium acetylsalicylate + Water
From the equation, we can see that the ratio of moles of acetylsalicylic acid to moles of NaOH is 1:1.
Therefore, moles of acetylsalicylic acid = 0.005984 moles
Step 3: Convert moles of acetylsalicylic acid to grams
To do this, we need to use the molar mass of acetylsalicylic acid, which is 180.16 g/mol.
mass of acetylsalicylic acid = moles of acetylsalicylic acid × molar mass
mass of acetylsalicylic acid = 0.005984 moles × 180.16 g/mol = 1.079 g
Step 4: Calculate the percentage of acetylsalicylic acid
To calculate the percentage, we can use the formula:
percentage = (mass of acetylsalicylic acid / mass of tablet) × 100
Given: mass of tablet = 0.726 g
percentage = (1.079 g / 0.726 g) × 100 ≈ 148.71%
Therefore, the percentage of acetylsalicylic acid in the tablet is approximately 148.71%.
No problem! I'll walk you through the steps to solve this problem.
Step 1: Calculate the number of moles of NaOH used in the titration.
To do this, you need to use the formula:
moles NaOH = Molarity (M) × Volume (L).
Given:
Molarity of NaOH (M) = 0.272 M
Volume of NaOH used (L) = ?
We don't have the volume of NaOH used yet. This information is missing from the question. Make sure you have the complete information before proceeding. Let's assume the volume of NaOH used is 25.0 mL (0.025L).
moles NaOH = 0.272 M × 0.025 L = 0.0068 moles of NaOH.
Step 2: Determine the number of moles of acetylsalicylic acid (aspirin) in the tablet.
To do this, we'll use the balanced equation between NaOH and acetylsalicylic acid:
NaOH + HCl → NaCl + H2O
From the stoichiometry of the equation, we know that 1 mole of NaOH reacts with 1 mole of acetylsalicylic acid.
Therefore, the number of moles of acetylsalicylic acid is also 0.0068 moles.
Step 3: Calculate the molar mass of acetylsalicylic acid.
The molar mass of acetylsalicylic acid (C9H8O4) can be found by adding up the atomic masses of carbon (12.01 g/mol), hydrogen (1.008 g/mol), and oxygen (16.00 g/mol).
Molar mass of acetylsalicylic acid = (9 × 12.01 g/mol) + (8 × 1.008 g/mol) + (4 × 16.00 g/mol) = 180.16 g/mol
Step 4: Calculate the mass of acetylsalicylic acid in the tablet.
To do this, we need to use the formula:
mass = number of moles × molar mass.
mass of acetylsalicylic acid = 0.0068 moles × 180.16 g/mol = 1.225 g
Step 5: Calculate the percentage of acetylsalicylic acid in the tablet.
The percentage can be calculated using the formula:
percentage = (mass of acetylsalicylic acid / mass of tablet) × 100.
Given:
mass of tablet = 0.726 g
percentage = (1.225 g / 0.726 g) × 100 = 169.20%
So, the percentage of acetylsalicylic acid in the tablet is approximately 169.20%.