Question

Upon decomposition, a sample of sodium bicarbonate produces 0.0118 g of sodium carbonate, Na2CO3. How many grams of water does it produce

Answer 1

2.00 × 10⁻³ g

Step-by-step explanation:

Step 1: Write the balanced decomposition reaction

2 NaHCO₃ ⇒ Na₂CO₃ + CO₂ + H₂O

Step 2: Calculate the moles corresponding to 0.0118 g of Na₂CO₃

The molar mass of Na₂CO₃ is 105.99 g/mol.

0.0118 g × 1 mol/105.99 g = 1.11 × 10⁻⁴ mol

Step 3: Calculate the moles of H₂O produced with 1.11 × 10⁻⁴ moles of Na₂CO₃

The molar ratio of Na₂CO₃ to H₂O is 1:1. The moles of H₂O produced are 1/1 × 1.11 × 10⁻⁴ mol = 1.11 × 10⁻⁴ mol.

Step 4: Calculate the mass corresponding to 1.11 × 10⁻⁴ moles of H₂O

The molar mass of H₂O is 18.02 g/mol.

1.11 × 10⁻⁴ mol × 18.02 g/mol = 2.00 × 10⁻³ g