# Mr. Quinn & Ms. Tom February 11, 2014 Aim: How do we determine the limiting reagent in a chemical reaction? Do Now: balance the following chemical equation.

## Presentation on theme: "Mr. Quinn & Ms. Tom February 11, 2014 Aim: How do we determine the limiting reagent in a chemical reaction? Do Now: balance the following chemical equation."— Presentation transcript:

Mr. Quinn & Ms. Tom February 11, 2014 Aim: How do we determine the limiting reagent in a chemical reaction? Do Now: balance the following chemical equation. ___ YCl 3 + ___ NbBr 5  __ YBr 3 + ___ NbCl 5

The Steps 1.Balance the equation 2.Solve for the amount of product formed for each reactant You will get different numbers 3.Whichever reactant formed a smaller amount of product is your limiting reagent.

Example 1: Carbon and Fluorine Graphite (C) burns in fluorine according to the following unbalanced equation. If 16 g of carbon are burned with 48 g of fluorine, what is the limiting reagent? 1.Balance the equation (list the elements, tally the elements, solve) C + F 2  CF 4

Example 1: Carbon and Fluorine 1 C + 2 F 2  1 CF 4 2.Find the molar mass of both reactants and one product Graphite (C) Fluorine (F 2 ) ElementNumberMassTotal ElementNumberMassTotal C112 F2 Sum of everything: CF 4 ElementNumberMassTotal C F Sum of everything:

Example 1: Carbon and Fluorine 3.Use dimensional analysis to predict the product formation from both reactants. Starting Mass (From problem) Reciprocal of Molar Mass Reactant 2 (F 2 ) Mole ratio from balanced equation (F 2 :AlF 3 ) Molar mass of product (AlF 3 ) Result (in g of AlF 3 ) X X X = Starting Mass (From problem) Reciprocal of Molar Mass Reactant 1 (C) Mole ratio from balanced equation (Al:AlF 3 ) Molar mass of product (AlF 3 ) Result (in g of AlF 3 ) X X X =

Example 2: Aluminum and Fluorine Aluminum (Al) burns in fluorine according to the following unbalanced equation. If 16 g of aluminum are burned with 57 g of fluorine, what is the limiting reagent? 1.Balance the equation (list the elements, tally the elements, solve) Al + F 2  AlF 3

Example 1: Aluminum and Fluorine 2 Al + 3 F 2  2 AlF 3 2.Find the molar mass of both reactants and one product Aluminum (Al) Fluorine (F 2 ) ElementNumberMassTotal ElementNumberMassTotal Al1 F Sum of everything: AlF 3 ElementNumberMassTotal Sum of everything:

Example 1: Aluminum and Fluorine 3.Use dimensional analysis to predict the product formation from both reactants. Starting Mass (From problem) Reciprocal of Molar Mass Reactant 2 (Al) Mole ratio from balanced equation Molar mass of product (AlF 3 ) Result (in g of AlF 3 ) X X X = Starting Mass (From problem) Reciprocal of Molar Mass Reactant 1 (Al) Mole ratio from balanced equation Molar mass of product (AlF 3 ) Result (in g of AlF 3 ) X X X =

Example 1: Sulfur and Fluorine Sulfur (S 8 ) burns in fluorine according to the following unbalanced equation. If 128 g of sulfur are burned with 144 g of fluorine, what is the limiting reagent? 1.Balance the equation (list the elements, tally the elements, solve) S 8 + F 2  SF 2

Example 1: Carbon and Fluorine 1 S 8 + 8 F 2  8 SF 2 2.Find the molar mass of both reactants and one product

Example 1: Carbon and Fluorine 3.Use dimensional analysis to predict the product formation from both reactants. Starting Mass (From problem) Reciprocal of Molar Mass Reactant 2 Mole ratio from balanced equation Molar mass of product Result X X X = Starting Mass (From problem) Reciprocal of Molar Mass Reactant 1 Mole ratio from balanced equation Molar mass of product Result X X X =