Final answer:
By converting the mass of ascorbic acid to grams, calculating the number of moles, and then using Avogadro's number to find the number of molecules, it's determined that 1025 mg of ascorbic acid contains 3.505 × 1021 molecules.
Step-by-step explanation:
To determine how many molecules of ascorbic acid (C6H8O6), also known as vitamin C, are contained in 1025 mg of ascorbic acid, we need to use the molecular mass of ascorbic acid and Avogadro's number. The molecular mass of ascorbic acid is 176 amu, which means 1 mole of ascorbic acid weighs 176 grams.
First, convert the mass from milligrams to grams:
1025 mg × 1 g/1000 mg = 1.025 g
Next, calculate the number of moles of ascorbic acid:
1.025 g × 1 mol/176 g = 0.00582 mol
Then, use Avogadro's number to convert moles to molecules:
0.00582 mol × 6.022 × 1023 molecules/mol = 3.505 × 1021 molecules
Therefore, there are 3.505 × 1021 molecules of ascorbic acid in 1025 mg of ascorbic acid, which corresponds to option (a).