If 0.066 mol of salicylic acid was added to 65.78 ml. of pentanol, what would be the concentration of the resulting solution in units of g solute//00 g solvent?
MW of salicylic acid = 138.12 g/mol
MW of pentanol – 88.15 g/mol
Density of pentanol – 0.8144 g/mL
The correct answer and explanation is :
The concentration of the resulting solution is approximately 17.02 g of salicylic acid per 100 g of pentanol.
Explanation:
To find the concentration of salicylic acid in pentanol, we need to follow a series of steps:
- Calculate the mass of salicylic acid:
- The number of moles of salicylic acid is given as 0.066 mol.
- The molar mass of salicylic acid is 138.12 g/mol.
- Therefore, the mass of salicylic acid can be calculated using the formula: [
\text{Mass of salicylic acid} = \text{Moles} \times \text{Molar mass}
]
[
\text{Mass of salicylic acid} = 0.066 \, \text{mol} \times 138.12 \, \text{g/mol} = 9.11 \, \text{g}
]
- Calculate the mass of pentanol:
- The volume of pentanol is 65.78 mL.
- The density of pentanol is 0.8144 g/mL.
- The mass of pentanol is calculated using the formula: [
\text{Mass of pentanol} = \text{Volume} \times \text{Density}
]
[
\text{Mass of pentanol} = 65.78 \, \text{mL} \times 0.8144 \, \text{g/mL} = 53.55 \, \text{g}
]
- Calculate the concentration:
- The concentration of solute (salicylic acid) in solvent (pentanol) is given by: [
\text{Concentration} = \frac{\text{Mass of solute}}{\text{Mass of solvent}} \times 100
]
[
\text{Concentration} = \frac{9.11 \, \text{g}}{53.55 \, \text{g}} \times 100 \approx 17.02\%
]
Thus, the concentration of salicylic acid in pentanol is approximately 17.02 g per 100 g of solvent.
Here is a bar plot showing the mass of salicylic acid (solute) and pentanol (solvent) used in the solution. As you can see, the mass of pentanol is significantly higher than that of salicylic acid, which is typical for solutions with a small amount of solute relative to the solvent. This visual aids in understanding the concentration calculation.