Answer:
43.72
Explanation:
that is the answer hope u liked it and I did this already along time ago
Molecular formula of ascorbic acid is 
Molar mass of ascorbic acid = 
Converting 500.0 mg of ascorbic acid to moles: We use molar mass of ascorbic acid to convert mass to moles.

Converting 500.0 mg of ascorbic acid to molecules: The conversion factor used is 1 mole = 

Answer:
0.78× 10 ²³ molecules
Explanation:
Given data:
Mass of pyridine = 10.35 g
Number of molecules = ?
Solution:
Number of moles of pyridine:
Number of moles = mass/molar mass
Number of moles = 10.35 g/ 79.1 g/mol
Number of moles = 0.13 mol
Number of molecules;
1 mole contain 6.022× 10 ²³ molecules
0.13 mol × 6.022× 10 ²³ molecules / 1mol
0.78× 10 ²³ molecules