Answer to Question #290348 in Chemistry for Bobby

Question

Determine the mass of nitrogen found in 8.85g of Pb(NO3)3

Answer 1

Solution:

Pb(NO₃)₃ is not the correct chemical formula.

Pb(NO₃)₂ is the correct chemical formula.

Considering the above, write down the chemical scheme:

Pb(NO₃)₂ → Pb + 2N + 6N

According to the scheme:

Moles of Pb(NO₃)₂ = Moles of N / 2

The molar mass of Pb(NO₃)₂ is 331.2 g/mol

Hence,

Moles of Pb(NO₃)₂ = (8.85 g) × (1 mol / 331.2 g) = 0.02672 mol

Moles of N = 2 × Moles of Pb(NO₃)₂ = 2 × 0.0267 mol = 0.05344 mol

The atomic weight of N is 14.0067 g/mol

Hence,

Mass of N = (0.05344 mol) × (14.0067 g / 1 mol) = 0.7485 g = 0.75 g

Mass of N = 0.75 g

Answer: The mass of nitrogen (N) is 0.75 grams