How many molecules of ascorbic acid (vitamin c, c6h8o6) are in a 500 mg tablet?

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.

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na