Question

Small quantities of oxygen can be prepared in the laboratory by heating potassium chlorate (KClO₃) (s). The equation for the reaction is 2KClO₃ → 2KCl + 3O₂. Calculate how many grams of O₂(g) can be produced from heating 33.7g KClO₃(s).

A. 18.9 g
B. 22.5 g
C. 33.7 g
D. 50.5 g

Answer 1

To calculate the grams of O₂ produced from heating KClO₃, use stoichiometry. The molar mass of KClO₃ is 122.55 g/mol. Using the molar ratio from the balanced equation, calculate the number of moles of O₂ produced. Finally, use the molar mass of O₂ to convert moles to grams.

Step-by-step explanation:

To calculate the grams of O₂ produced from heating KClO₃, we need to use stoichiometry. First, determine the molar mass of KClO₃ by adding the atomic masses of each element: (1 mol K) + (1 mol Cl) + (3 mol O) = 122.55 g/mol. Next, use the balanced equation to determine the molar ratio between KClO₃ and O₂: 2 moles of KClO₃ produce 3 moles of O₂. Then, use the molar mass of O₂ to convert moles of O₂ to grams: (3 moles O₂) × (32.00 g/mol) = 96.00 g.

To find the grams of O₂ produced from 33.7 g of KClO₃, set up a proportion: (96.00 g O₂)/(1 mol KClO₃) = (x g O₂)/(33.7 g KClO₃). Cross multiply and solve for x to find the number of grams of O₂ produced from 33.7 g of KClO₃: x = (33.7 g KClO₃) × (96.00 g O₂) / (122.55 g KClO₃) = 26.35 g O₂.