How many molecules are produced from 25.0 L of oxygen gas? 2 H2 (g) + O2 (g) --> 2 H2O (g)

Answer 1

Given the reaction: 2H₂(g) + O₂(g) → 2H₂O(g)

Assuming STP (because no thermodynamic data was given, 22.4 L / 1 mol of gas) and excess H₂:

(25.0 L O₂)(1 mol O₂ / 22.4 L) = 1.12 mol O₂

Using standard stoichiometric method,

(1.12 mol O₂)(2 mol H₂O/1 mol O₂) = 2.24 mol H₂O

Using Avogadro's Number,

(2.24 mol H₂O)(6.022*10²³ molecules / 1 mol) = 1.35*10²⁴ molecules of H₂O were produced.