How many molecules of ascorbic acid (vitaminC,

C6H8 O6) are in a 500 mg

tablet?

1.71 * 10²¹ molecules

Explanation:

1 gram is equal to 1000 milligrams. The mass in grams corresponding to 500 mg is:

500 mg * (1 g / 1000 mg) = 0.500 g

The molar mass of ascorbic acid is 176.12 g/mol. The moles corresponding to 0.500 grams of ascorbic acid are:

0.500 g * (1 mol / 176.12 g) = 0.00284 mol

In 1 mole of ascorbic acid, there are 6.02 * 10²³ molecules of ascorbic acid (Avogadro's number). The molecules in 0.00284 moles are:

0.00284 mol * (6.02 * 10²³ molecules / 1 mol) = 1.71 * 10²¹ molecule

1) molar mass of the C6H8O6, you need to consult the atomic weight of the C, H and O atoms that are in the periodic table: C is 12; H is 1; O is 16 (12x6) + (1x8) + (16x6) = 176g/mol 176 g = 1 mol 0,5 g = x mol 500mg = 0,5 grams molar mass = mass: moles 176 = 0,5: x x = 2,84 x 10⁻³ mol 2) To find the number of molecules present in those 2,84 x 10⁻³ mol we need to multiple the moles by the Avogadro's constant No. of molecules = Avogadro's constant x n° of moles No. of molecules = 6.022 x 10²³ x 2,84 x 10⁻³ = 1.71 x 10²¹ molecules of vit C.