Question

Bam makes a second solution, adding 5.01 g of Co(CH3COO)2 to 39.93 mL of H2O. Calculate the concentration of this solution in mole fraction.

A. 0.001
B. 0.005
C. 0.01
D. 0.1

Answer 1

To find the mole fraction of Co(CH3COO)2, we divide the moles of solute by the total moles in the solution. The calculation reveals that the correct answer is approximately 0.01, thus the answer C. 0.01 is correct.

Step-by-step explanation:

To calculate the concentration of the cobalt(II) acetate solution in mole fraction, we need to know the number of moles of solute (Co(CH3COO)2) and the total number of moles in the solution, including the water.

1. First, calculate the number of moles of Co(CH3COO)2 by dividing the mass of the solute by its molar mass. The molar mass of Co(CH3COO)2 is 249.08 g/mol. So the number of moles would be 5.01 g / (249.08 g/mol) = 0.0201 mol.
2. Next, calculate the number of moles of water. The molar mass of H2O is 18.015 g/mol, and 39.93 mL of water has a mass of approximately 39.93 g, given the density of water is close to 1 g/mL. Therefore, the number of moles of water is 39.93 g / (18.015 g/mol) = 2.217 mol.
3. The total number of moles in the solution is the sum of the moles of Co(CH3COO)2 and H2O, which is 0.0201 mol + 2.217 mol = 2.2371 mol.
4. Finally, to find the mole fraction of Co(CH3COO)2, we divide the moles of Co(CH3COO)2 by the total moles: 0.0201 mol / 2.2371 mol = 0.00898, which can be rounded to 0.009 when considering significant figures.

Therefore, the correct answer is C. 0.01, representing the mole fraction of Co(CH3COO)2 in the solution.