1. Balanced Chemical Equation:
The decomposition of baking soda is represented by the following balanced chemical equation:
2 NaHCO₃(s) → Na₂CO₃(s) + H₂O(g) + CO₂(g)
This equation tells us that 2 moles of sodium bicarbonate (NaHCO₃) decompose to produce 1 mole of sodium carbonate (Na₂CO₃), 1 mole of water (H₂O), and 1 mole of carbon dioxide (CO₂).
2. Molar Masses:
* NaHCO₃ (baking soda): 84.01 g/mol
* Na₂CO₃ (sodium carbonate): 105.99 g/mol
* H₂O (water): 18.02 g/mol
* CO₂ (carbon dioxide): 44.01 g/mol
3. Stoichiometry Calculations:
* Step 1: Moles of Baking Soda:
Convert the mass of baking soda (42.0 g) to moles using its molar mass:
moles of NaHCO₃ = (42.0 g) / (84.01 g/mol) = 0.500 mol
* Step 2: Moles of Products:
Use the mole ratios from the balanced equation to find the moles of each product:
* moles of Na₂CO₃ = (0.500 mol NaHCO₃) * (1 mol Na₂CO₃ / 2 mol NaHCO₃) = 0.250 mol
* moles of H₂O = (0.500 mol NaHCO₃) * (1 mol H₂O / 2 mol NaHCO₃) = 0.250 mol
* moles of CO₂ = (0.500 mol NaHCO₃) * (1 mol CO₂ / 2 mol NaHCO₃) = 0.250 mol
* Step 3: Grams of Products:
Convert the moles of each product to grams using their respective molar masses:
* grams of Na₂CO₃ = (0.250 mol) * (105.99 g/mol) = 26.5 g
* grams of H₂O = (0.250 mol) * (18.02 g/mol) = 4.51 g
* grams of CO₂ = (0.250 mol) * (44.01 g/mol) = 11.0 g
Therefore:
* 26.5 grams of sodium carbonate (Na₂CO₃) are produced.
* 4.51 grams of water (H₂O) are produced.
* 11.0 grams of carbon dioxide (CO₂) are produced.
