Final answer:
To calculate the mass of formaldehyde in a solution, multiply the number of moles (found by multiplying molarity and volume in liters) by the molar mass of formaldehyde, resulting in 79.39 grams of formaldehyde in the given solution.
Step-by-step explanation:
The subject of the question involves determining the number of grams of formaldehyde in a given volume and molarity of a formaldehyde aqueous solution. To find the mass of formaldehyde present, we must first calculate the number of moles of formaldehyde using the formula:
mol = molarity × volume
In this case, we have a molarity (M) of 15.0 M and a volume of 176.2 mL, which must be converted into liters (L) to use the molarity formula:
176.2 mL × (1 L / 1000 mL) = 0.1762 L
Now we can calculate:
moles of formaldehyde = 15.0 M × 0.1762 L = 2.643 moles
Next, knowing the molar mass of formaldehyde (H₂CO) which is approximately 30.031 g/mol, we calculate the mass:
mass of formaldehyde = moles of formaldehyde × molar mass
mass of formaldehyde = 2.643 moles × 30.031 g/mol = 79.39 grams
Therefore, the mass of formaldehyde in 176.2 mL of a 15.0 M aqueous solution is 79.39 grams.