Suppose 5.00 gram of a mixture of aspirin, caffeine, and acetanilide was dissolved in enough solvent (methylene chloride) to make a total of 100.00 mL volume. You took 10.00 mL from it and isolated its components using the same protocol you did in the lab. You obtained:
Aspirin (180.16 g/mol ) = 0.082 gram; Caffeine (194.19 g/mol ) = 0.21 gram; acetanilide (135.16 g/mol )= 0.150 g
1. What is the % of each component in the original mixture?
2. If the total number of moles of components in 5.00 gram of the mixture is 0.600 mole, what is the molar % composition of each component in the mixture?
% aspirin = (0.082/5.00)*100 = ?
%caffeine = )0.21/5.00)*100 = ?d
etc for acetanilide.
For #2, convert grams given in the problem to mols. mol = grams/molar mass = ?
Then mol% aspirin = (mols aspirin/0.600)*100 = ?
etc. for the others.
To find the percentage of each component in the original mixture, you need to divide the mass of each component by the total mass of the mixture and then multiply by 100.
1. To find the percentage of aspirin:
- Mass of aspirin = 0.082 g
- Total mass of the mixture = 5.00 g
- Percentage of aspirin = (0.082 g / 5.00 g) * 100% = 1.64%
2. To find the percentage of caffeine:
- Mass of caffeine = 0.21 g
- Total mass of the mixture = 5.00 g
- Percentage of caffeine = (0.21 g / 5.00 g) * 100% = 4.20%
3. To find the percentage of acetanilide:
- Mass of acetanilide = 0.150 g
- Total mass of the mixture = 5.00 g
- Percentage of acetanilide = (0.150 g / 5.00 g) * 100% = 3.00%
Therefore, the percentages of each component in the original mixture are:
- Aspirin: 1.64%
- Caffeine: 4.20%
- Acetanilide: 3.00%
To find the molar percentage composition of each component in the mixture, you need to divide the moles of each component by the total moles and then multiply by 100.
1. To find the moles of each component:
- Moles of aspirin (n_aspirin) = mass of aspirin / molar mass of aspirin
= 0.082 g / 180.16 g/mol = 0.000455 mol
- Moles of caffeine (n_caffeine) = mass of caffeine / molar mass of caffeine
= 0.21 g / 194.19 g/mol = 0.001081 mol
- Moles of acetanilide (n_acetanilide) = mass of acetanilide / molar mass of acetanilide
= 0.150 g / 135.16 g/mol = 0.001110 mol
2. To find the total moles of components in the mixture:
- Total moles = n_aspirin + n_caffeine + n_acetanilide
= 0.000455 mol + 0.001081 mol + 0.001110 mol = 0.002646 mol
3. To find the molar percentage of each component:
- Molar percentage of aspirin = (n_aspirin / total moles) * 100%
- Molar percentage of caffeine = (n_caffeine / total moles) * 100%
- Molar percentage of acetanilide = (n_acetanilide / total moles) * 100%
Therefore, the molar percentage composition of each component in the mixture is:
- Aspirin: (0.000455 mol / 0.002646 mol) * 100% = 17.22%
- Caffeine: (0.001081 mol / 0.002646 mol) * 100% = 40.88%
- Acetanilide: (0.001110 mol / 0.002646 mol) * 100% = 41.90%