How many moles of steric acid are contained in 0.25mL of a hexane solution containing 5.4x10^-4 grams of steric acid/L? (Hint: g/L x L = g/ (g/mol)=mol).
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To find the number of moles of steric acid in the given solution, we can follow these steps:
Step 1: Calculate the number of grams of steric acid in 0.25 mL of the solution.
Given: Volume of solution = 0.25 mL and Concentration of steric acid = 5.4x10^-4 grams/L
First, convert the mL to L:
0.25 mL * (1 L / 1000 mL) = 0.00025 L
Now, calculate the number of grams of steric acid in the given volume:
Grams of steric acid = 0.00025 L * 5.4x10^-4 grams/L = 1.35x10^-7 grams
Step 2: Convert the grams of steric acid to moles.
For this calculation, we need the molar mass of steric acid, which is C18H36O2.
The atomic masses of C, H, and O are:
C: 12.01 g/mol
H: 1.01 g/mol
O: 16.00 g/mol
To calculate the molar mass of steric acid, we multiply the atomic masses by their respective subscripts and then sum them up:
Molar mass of steric acid = (18 * 12.01 g/mol) + (36 * 1.01 g/mol) + (2 * 16.00 g/mol)
= 270.52 g/mol
Now, we can convert the grams of steric acid to moles using the molar mass:
Moles of steric acid = 1.35x10^-7 grams / 270.52 g/mol
≈ 4.99x10^-10 moles
Thus, there are approximately 4.99x10^-10 moles of steric acid in 0.25 mL of the hexane solution.