Establish the molecular formula of ascorbic acid if, upon combustion of 1 mol, 6 mol of carbon dioxide

Establish the molecular formula of ascorbic acid if, upon combustion of 1 mol, 6 mol of carbon dioxide and 4 mol of water are formed, and its M = 176 g / mol (СxHyOz)

Given:
n (СxHyOz) = 1 mol
n (CO2) = 6 mol
n (H2O) = 4 mol
M (СxHyOz) = 176 g / mol

Find:
СxHyOz -?

Solution:
1) СxHyOz + O2 -> 6CO2 + 4H2O;
2) n (C in СxHyOz) = n (C in CO2) = n (CO2) = 6 mol;
3) x = 6;
4) n (H in СxHyOz) = n (H in H2O) = n (H2O) * 2 = 4 * 2 = 8 mol;
5) y = 8;
6) M (CxHyOz) = Mr (CxHyOz) = Ar (C) * N (C) + Ar (H) * N (H) + Ar (O) * N (O);
176 = 12 * 6 + 1 * 8 + 16 * z;
176 = 80 + 16z;
16z = 96;
z = 6;
7) The molecular formula of ascorbic acid is C6H8O6.

Answer: The molecular formula of ascorbic acid is C6H8O6.