2C 2 H 6 + 7O 2 * **>4CO 2 + 6H 2 O if 7.0 g of C 2 H 6 react with 18 g of O 2, how many grams of water will be produced

grams H₂O produced = 8.7 grams

Explanation:

Given 2C₂H₆ (g) + 7O₂ (g) = > 4CO₂ (g) + 6H₂O (l)

7g 18g? g

Plan = > Convert gms to moles = > determine Limiting reactant = > solve for moles water = > convert moles water to grams water

Moles Reactants

moles C₂H₆ = 7g/30g/mol = 0.233mol

moles O₂ = 18g/32g/mol = 0.563mol

Limiting Reactant = > (Test for Limiting Reactant) Divide mole value by respective coefficient of balanced equation; the smaller number is the limiting reactant.

moles C₂H₆/2 = 0.233/2 = 0.12

moles O₂/7 = 0.08

Limiting Reactant is O₂

Moles and Grams of H₂O:

Use Limiting Reactant moles (not division value) to calculate moles of H₂O.

moles H₂O = 6/7 (moles O₂) = 6/7 (0.562) moles H₂O = 0.482 mole H₂O yield

grams H₂O = (0.482mol) (18g·mol⁻¹) = 8.7 grams H₂O