Answer:
a) 4C₆H₉O₉ + 15O₂ ---> 18H₂O + 24CO₂
b) 20.496 grams of oxygen is required to completely combust 38.43 grams of the white powder.
Note: The given molecular of the unknown white powder is C₆H₉O₉ according to the attachment below.
Explanation:
a) Balanced equation of reaction:
4C₆H₉O₉ + 15O₂ ---> 18H₂O + 24CO₂
b) molar mass of C₆H₉O₉ =225 g/mol; molar mass of O₂ = 32 g/mol
number of moles of C₆H₉O₉ in 38.43 g = 38.43/225 g/mol = 0.1708 moles
number of moles of oxygen required for combustion = 15/4 * 0.1708
number of moles of oxygen = 0.6405
mass of 0.6405 moles of oxygen = 0.6405 moles * 32 g/mol = 20.496 g
20.496 grams of oxygen is required to completely combust 38.43 grams of the white powder.