Determine the mass of NaCl and sodium chloride

Question

Part 1. A chemist reacted 12.0 liters of F₂ gas with NaCl in the laboratory to form Cl₂ gas and NaF. Use the ideal gas law equation to determine the mass of NaCl that reacted with F₂ at 280. K and 1.50 atm.

F₂ + 2NaCl → Cl₂ + 2NaF

Part 2. Explain how you would determine the mass of sodium chloride that can react with the same volume of fluorine gas at STP. (8 points)

Answer 1

F₂ + 2NaCl → Cl₂ + 2NaF

Determine moles of F₂:

PV = nRT

n = PV/RT = (1.50 atm)(12.0 L) / (0.0821 Latm/Kmol)(280K)

n = moles F2 = 0.783 mols

Moles NaCl reacting:

0.783 mols N₂ x 2 mols NaCl/mole F₂ = 1.57 mols NaCl reacting

Mass NaCl reacting:

1.57 mols NaCl x 58.4 g / mol = 91.5 g NaCl reacting

The same volume (12.0) L of F₂ at STP = 12.0 L x 22.4 mol/L = 268.8 moles F₂

The same mole ratio of 2 mols NaCl : 1 mol F₂ exists, so you'd need 2 x 268.8 mols NaCl

Multiply this by 58.4 g / mol for NaCl to get grams of NaCl reacting @ STP (31,400 g)