Question #de22e

1 Answer
Sep 12, 2017

Work from the known mass and molar ratios of the equation.

Explanation:

As a “stoichiometry” question we will assume that all compounds are in the exact amounts, as shown by the equation. Given the molar quantities, we can work backwards from the one given mass quantity to find the rest of the component values.

O_2 is 88g, and its molecular weight is 32 g/mol (for the diatomic molecule). So, we have a total of 88/32 = 2.75 moles of O_2, or 5.50 moles of O.

The given stoichiometric equation shows that includes 9 moles of O_2 (3 in the glucose, 6 'free' oxygen):

6CO_2 + 6H_2O -> C_6H_(12)O_6 + 6O_2

Adjusting that for the given amount of 2.75 moles, each atomic factor must be reduced by 2.75/9 = 0.306

That means in our actual reaction we have 6C xx 0.306 = 1.83 moles carbon and 6H_2 xx 0.306 = 1.83 moles of H_2.

Converting those to masses we obtain:
1.83 mol xx 12 (g/(mol_C)) = 22g carbon (C).
1.83 mol xx 2 (g/(mol_(H_2))) = 3.66g hydrogen (H_2).