Question

Use the chemical equation and the table to answer the question.

Pb(NO3)2(aq) + 2KBr(aq) → PbBr2(s) + 2KNO3(aq)

Molar Mass (g/mol) of Reactants and Products Involved in a Reaction
Reactant or Product Molar Mass (g/mol)
Pb(NO3)2 331
KBr 119
PbBr2 367
KNO3 101
When 496.5 grams of Pb(NO3)2 reacts completely with KBr, how much will the total mass of the products be?

(1 point)
Responses

853.5 g

550.5 g

496.5 g

702.0 g

Answer 1

853.5 g

Work:
- Moles Pb(NO3)2 = 496.5 g / 331 g·mol⁻¹ = 1.50 mol
- Required KBr = 2 × 1.50 mol = 3.00 mol → mass KBr = 3.00 × 119 g·mol⁻¹ = 357.0 g
- Total mass of reactants = 496.5 + 357.0 = 853.5 g
By conservation of mass, total mass of products = 853.5 g.