Today’s Do Now: Cooking with Chemistry “Let’s Make a Cake”

Recipe for 1 CAKE 2 cups flour 2 eggs 1 cup sugar 1 ½ Tbsp. baking powder 1 cup water 1 / 3 cup oil (Mix all ingredients and bake until done)

Let’s check to see what we have in our kitchen… 14 cups of flour 9 cups of sugar 3 1/3 cups of oil 4 eggs 15 Tbsp. baking powder unlimited water (indoor plumbing)

Use the recipe and the amounts available in our kitchen to answer the following questions… 1.How many cakes can be made? 2.What is the ingredient that will run out first? How do you know? 3.How much flour will remain?

Use the recipe and the amounts available in our kitchen to answer the following questions… 1.How many cakes can be made? 2.What is the limiting ingredient? 3.How much flour will remain? 4.How much baking powder will remain? Recipe for 1 CAKE 2 cups flour 2 eggs 1 cup sugar 1 ½ Tbsp. baking powder 1 cup water 1 / 3 cup oil (Mix all ingredients and bake until done)

Use the recipe and the amounts available in our kitchen to answer the following questions… 1.How many cakes can be made? 2.What is the limiting ingredient? 3.How much flour will remain? 4.How much baking powder will remain? Recipe for 1 CAKE 2 cups flour 2 eggs 1 cup sugar 1 ½ Tbsp. baking powder 1 cup water 1 / 3 cup oil (Mix all ingredients and bake until done) 14 cups of flour 9 cups of sugar 3 1/3 cups of oil 4 eggs 15 Tbsp. baking powder unlimited water (indoor plumbing)

By the end of today’s class period, I will be able to… Define limiting reactant and excess reactant Solve for the limiting reactant using stoichiometry

Today’s Game Plan Cooking with Chemistry 10 minutes Limiting Reagent Introduction 15 minutes Work it Out Together 10 minutes Excess Reactant Remaining 30 minutes Independent Practice 15 minutes Exit Ticket 10 minutes

2 Necessary Definitions Limiting Reactant: the reactant that runs out first and thus limits the amounts of products that can form Excess Reactant: the reactant that is not completely consumed in the reaction

A chemical reaction is similar to a recipe…

We can make more than the recipe calls for…

6 mol of H 2 are reacted with 4 mol of F 2. Find the limiting reactant, the moles of product formed, and the moles of excess reactant remaining after the reaction. We can use any starting amount (and have some items left over)… H 2 + F 2 2HF

6 mol of H 2 are reacted with 4 mol of F 2. Find the limiting reactant, the moles of product formed, and the moles of excess reactant remaining after the reaction. We can use any starting amount (and have some items left over)… H 2 + F 2 2HF

6 mol of H 2 are reacted with 4 mol of F 2. Find the limiting reactant, the moles of product formed, and the moles of excess reactant remaining after the reaction. We can use any starting amount (and have some items left over)… H 2 + F 2 2HF

Today’s Game Plan Cooking with Chemistry 10 minutes Limiting Reagent Introduction 15 minutes Work it Out Together 10 minutes Excess Reactant Remaining 30 minutes Independent Practice 15 minutes Exit Ticket 10 minutes

SiO 2 + 4HF  SiF 4 + 2H 2 O 3.2 mol of SiO 2 is reacted with 15.1 mol of HF. How many grams of water will form? What is the limiting reactant? What is excess reactant?

You Try… Nitrogen gas can be prepared by passing gaseous ammonia over solid copper(II) oxide at high temperatures. The other products of the reaction are solid copper and water vapor. How many moles of N 2 are formed when 18.1g of NH 3 is reacted with 90.4g of CuO? 2NH 3 (g) + 3CuO(s)  N 2 (g) + 3Cu(s) + 3H 2 O(g) 1. Take 30 seconds to circle what you are starting with and underline the information you are trying to find. 2. Take 3 minutes to solve your two stoichiometry problems and identify the amount of N 2 formed. 3. Take 1 minute to write a complete sentence explaining what the limiting reactant is in the problem and how you know.

Today’s Game Plan Cooking with Chemistry 10 minutes Limiting Reagent Introduction 15 minutes Work it Out Together 10 minutes Excess Reactant Remaining 30 minutes Independent Practice 15 minutes Exit Ticket 10 minutes

By the end of today’s class period, I will be able to… determine the amount of excess reactant left over after the limiting reactant is completely consumed

The Bicycle Factory… 2Tires + 1Frame = 1Bicycle

The Bicycle Factory… 2Tires + 1Frame = 1Bicycle If I have 16 Tires & 7 Frames how many bicycles can be made, and what pieces will be left over?

2H 2 + O 2 2H 2 O When 25.8 moles of Oxygen react with 7.55 moles of Hydrogen, how many grams of H 2 O will be produced? What is the limiting reactant? The excess reactant? How much of the excess reactant will remain?

4NH 3 + 5O 2  4NO + 6H 2 O If 7.55g NH 3 are reacted with 9.3 grams of O 2 how many grams of water will form? What is the limiting reactant? How many grams of the excess reactant will remain?

Today’s Game Plan Cooking with Chemistry 10 minutes Limiting Reagent Introduction 15 minutes Work it Out Together 10 minutes Excess Reactant Remaining 30 minutes Independent Practice 15 minutes Exit Ticket 10 minutes

Today’s Game Plan Cooking with Chemistry 10 minutes Limiting Reagent Introduction 15 minutes Work it Out Together 10 minutes Excess Reactant Remaining 30 minutes Independent Practice 15 minutes Exit Ticket 10 minutes

Write a letter to an ‘absent’ scholar In your letter, describe how to determine the limiting reactant and how much excess remains based on a chemical reaction You may write your letter on the back of your exit ticket.