Dr. Crofoot RIM High School

Dr. Crofoot RIM High School
Chemistry Chemical Reactions 1st SEMESTER, Unit 2-2 Dr. Crofoot RIM High School

Chemical Reactions 10/27/2017 Starter / Plicker
How many grams of oxygen in 3.0 moles of K2SO4? 12 grams 48 grams 64 grams 190 grams

Chemical Reactions 10/27/17 Write in Notebook
The Mole and Chemical Formula Example problems on the board. What is the molar mass of Sodium Nitrate, NaNO3? How many moles of Nitrate in 10 moles of NaNO3? How many grams of Nitrate in 10 moles of NaNO3? How many grams of Nitrate in 150 grams of NaNO3? How many moles of Al ions are in 45 grams of alumina, Al2O3? How many grams of carbon in 15 grams of Benzoyl Peroxide, C14H10O4? How many nitrogen atoms in 25.0 grams of hydrazine, N2H4? How many moles of silver can be recovered from 250 grams of Ag2S?

Chemical Reactions10/27/17 Home Work Chemical Reactions
Name Period Home Work Sheet Chemical Reactions Start your Two-Week Homework Sheet Use the format shown to the right!!!!! Do Questions from Chapter 11: 115, 116, 120, 126, 131 Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s

How many grams of oxygen in 36 moles of NaNO3? 16 grams 48 grams 140 grams 1700 grams

Chemical Reactions 10/30/17 Do not Write in Notebook Stoichiometry
Let say you went into the business of building wagons. Your suppliers provide you the following in the quantities listed: 12Wh Ax Ca Ha → 6Wh4Ax2CaHa How many wagons can you make and what would be the total mass of those wagons? Wheels Axles Cart Handle Parts per box 2 3 1 Parts in the box Mass per part 250 g/wheel 100 g/ axle 500 g/cart 150 g/handle Mass on hand 60,000 g 1200 g 5000 g 1500 g Molecule Wt. Wagon?______

Chemical Reactions 10/30/17 Do not Write in Notebook Stoichiometry
The coefficients and subscripts in chemical formula and chemical reactions can be used to predict amounts in chemical reactions. For example, When gasoline burns in your car engine, chemistry predicts how much oxygen from the air is required to burn a specific amount of gasoline. Or, if you need to know how much salicylic acid is required to make to make 500 grams of aspirin? Chemistry can predicts this information. If you put a candle in a jar, will the candle burn down, or will you run out of oxygen first? Chemistry can predict this information.

Chemical Reactions 10/30/17 Write in Notebook Stoichiometry
Stoichiometry: The study of quantitative relationships between amounts of reactants used in and products formed by a chemical reaction. Stoichiometry is based on conservation of mass and the necessity of having the same mass or moles of each element on both sides of a chemical equation. We will look at how to determine the following for reactant – product relationships: Mole : Mole Mole : Mass Mass : Mole Mass : Mass

Mole : Mole 2C6H O2 → 12CO2 + 14H2O How many moles of oxygen are required to burn 15.0 moles of hexane? 15.0 moles of hexane x 19 𝑚𝑜𝑙𝑒𝑠 𝑂2 2 𝑚𝑜𝑙𝑒𝑠 𝐶6𝐻14 = 143 moles of oxygen

Name Period Home Work Sheet Chemical Reactions Start your Two-Week Homework Sheet Use the format shown to the right!!!!! Do Questions from Chapter 12: 56, 57, 61, 62, 63 Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s

How many moles of oxygen in 36 grams of NaNO3? NaNO3 has a molecular weight of 85 g/mole. 0.42 grams 1.3 grams 2.4 grams 7.1 grams

Mole : Mass 2C6H O2 → 12CO2 + 14H2O How many grams of oxygen are required to burn 15.0 moles of hexane? 15.0 moles of hexane x 19 𝑚𝑜𝑙𝑒𝑠 𝑂2 2 𝑚𝑜𝑙𝑒𝑠 𝐶6𝐻14 x 32 𝑔𝑟𝑎𝑚𝑠 𝑂2 1𝑚𝑜𝑙𝑒𝑠 𝑂2 = 4560 grams of oxygen

Mass : Mole 2C6H O2 → 12CO2 + 14H2O How many moles of oxygen are required to burn 15.0 grams of hexane? 15.0 grams of hexane x 1 𝑚𝑜𝑙𝑒𝑠 𝐶6𝐻 𝑔𝑟𝑎𝑚𝑠 𝐶6𝐻14 x 19 𝑚𝑜𝑙𝑒𝑠 𝑂2 2 𝑚𝑜𝑙𝑒𝑠 𝐶6𝐻14 = 1.66 moles of oxygen

Name Period Home Work Sheet Chemical Reactions Start your Two-Week Homework Sheet Use the format shown to the right!!!!! Do Questions from Chapter 12: 64, 65, 67, 68 (hydrazine is N2H4 not N2H2) Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s

When ignited with hydrogen peroxide (H2O2), how many moles of hydrazine (N2H4) are required to produce 36 grams of water (H2O). N2H4 + 2H2O2 → N2 + 4H2O 0.5 moles 1.0 moles 2.0 moles 4.0 moles

Chemical Reactions 11/1/17 Write in Notebook Stoichiometry Mass : Mass
2C6H O2 → 12CO2 + 14H2O How many grams of oxygen are required to burn 15.0 grams of hexane? 15.0 grams of hexane x 1 𝑚𝑜𝑙𝑒𝑠 𝐶6𝐻 𝑔𝑟𝑎𝑚𝑠 𝐶6𝐻14 x 19 𝑚𝑜𝑙𝑒𝑠 𝑂2 2 𝑚𝑜𝑙𝑒𝑠 𝐶6𝐻14 x 32 𝑔𝑟𝑎𝑚𝑠 𝑂2 1 𝑚𝑜𝑙𝑒𝑠𝑂2 = 53.0 g O2

Chemical Reactions 11/1/17 Write in Notebook Stoichiometry Mass : Mass
N2H4 + 2H2O2 → N2 + 4H2O How many grams of water can be produced from 45 grams of hydrazine when ignited with hydrogen peroxide? 45.0 grams of N2H4 x 1 𝑚𝑜𝑙𝑒𝑠 𝑁2𝐻4 32 𝑔𝑟𝑎𝑚𝑠 𝑁2𝐻4 x 4 𝑚𝑜𝑙𝑒𝑠 𝐻2𝑂 1 𝑚𝑜𝑙𝑒𝑠 𝑁2𝐻4 x 18 𝑔𝑟𝑎𝑚𝑠 𝐻2𝑂 1 𝑚𝑜𝑙𝑒𝑠 𝐻2𝑂 = 101 g H2O

Name Period Home Work Sheet Chemical Reactions Start your Two-Week Homework Sheet Use the format shown to the right!!!!! Do Questions from Chapter 12: 70, 71(Ca=Sr), 73(CO not H2), 74a(Cu not Au) Thursday and Friday are Lab Days. Bring something to tie long hair back! Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s

What is the mass of iron (III) sulfide produced from 7.00 grams of iron in the following reaction? 16Fe + 3S8 → 8Fe2S3 3.50 grams 7.00 grams 13.0 grams 52.1 grams

How much glucose can be produced from 88.0 grams of carbon dioxide? 6CO2 + 6H2O → C6H12O6 + 6O2 10.0 grams 14.0 grams 60.0 grams 360 grams

How many grams of propane is required to produce 88.0 grams of carbon dioxide? C3H8 + 5O2 → 4H2O + 3CO2 29.3 grams 48.6 grams 88.0 grams 264 grams

Stoichiometry (Limiting Reactant) We have been doing stoichiometric calculations based on reaction scenarios where the amounts of reactants were the correct amounts needed. If there is an excess of all but one of the reactants, then that reactant is the limiting reactant. The limiting reactant then determines how much of each product can be produced based on mole ratios.

Chemical Reactions 11/6/17 Do not Write in Notebook
Stoichiometry (Limiting Reactant) In wagon analogy, if you had only 600 grams of axles (2 boxes) and the original masse of the rest of the parts, then you could only make 3 wagons. 12Wh Ax Ca Ha → 6Wh4Ax2CaHa The axles are then the limiting reactant. You can only make 3 wagons and you’ll have parts left over. Wheels Axles Cart Handle Parts per box 2 3 1 Parts in the box Mass per part 250 g/wheel 100 g/ axle 500 g/cart 150 g/handle Mass on hand 60,000 g 600 g 5000 g 1500 g

Stoichiometry (Limiting Reactant) To determine which reactant is the limiting reactant: Divide the moles of each reactant given in the problem by the corresponding coefficient from the balanced chemical reaction equation. The smallest of these ratios is the limiting reactant. Example: What is the limiting reactant for the reaction to produce ammonia, if we start with 4 moles of nitrogen and 9 moles of hydrogen? 1N H → NH3 4 moles/1moles 9moles/3moles Hydrogen has the smallest ratio, it is the limiting reagent.

Stoichiometry (Limiting Reactant) To determine which reactant is the limiting reactant if starting with mass: Determine the moles of each reactant. Divide the moles of each reactant given in the problem by the corresponding coefficient from the balanced chemical reaction equation. The smallest of these ratios is the limiting reactant. Example: What is the limiting reactant for the reaction to produce ammonia, if we start with 42 grams of nitrogen and 10 grams of hydrogen? 1N H → NH3 42gx 1 𝑚𝑜𝑙𝑒 𝑁2 28 𝑔 = gx 1 𝑚𝑜𝑙𝑒 𝐻2 2 𝑔 =5 1.5 moles/1moles moles/3moles Nitrogen has the smallest ratio, it is the limiting reagent.

Name Period Home Work Sheet Chemical Reactions Start your Two-Week Homework Sheet Use the format shown to the right!!!!! Do Questions from Chapter 12: 76, 81 Only determine the Limiting Reactant in the following questions: 77, 78, 79, 82,83 Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s

What is the limiting reactant in the following combustion reaction if we start with 10.0 grams of propane and 40.0 grams oxygen? C3H8 + 5O2 → 4H2O + 3CO2 propane oxygen water carbon dioxide

Stoichiometry (Limiting Reactant) Once you have determined which reactant is the limiting reactant, you can use its number of moles to calculate the number of moles or mass of the other reactants that will be used or the amount of each product that will be produced. Example: How much ammonia will be produced, if we start with 42 grams of nitrogen and 10 grams of hydrogen? N2 + 3H2 → 2NH3 42gx 1 𝑚𝑜𝑙𝑒 𝑁2 28 𝑔 =1.5mN2 10gx 1 𝑚𝑜𝑙𝑒 𝐻2 2 𝑔 =5.0mH2 1.5 moles/1moles 5moles/3moles 1.5 moles N2 x 2 𝑚𝑜𝑙𝑒 𝑁𝐻3 1 𝑚𝑜𝑙𝑒 𝑁2 𝑥 17 𝑔 𝑁𝐻3 1 𝑚𝑜𝑙𝑒 𝑁𝐻3 = = 51 grams of NH3 Nitrogen has the smallest ratio, it is the limiting reagent.

Stoichiometry (Limiting Reactant) Example 2 How much carbon dioxide will be produced, if we start with 10.0 grams of propane and 40.0 grams of oxygen? C3H8 + 5O2 → 4H2O + 3CO2 10gx 1 𝑚𝑜𝑙𝑒 𝐶3𝐻8 44 𝑔 =0.227mC3H8 40gx 1 𝑚𝑜𝑙𝑒 𝑂2 32 𝑔 =1.25mO moles/1moles 1.25moles/5moles Propane has the smallest ratio, it is the limiting reagent. =0.227 moles C3H8 x 3 𝑚𝑜𝑙𝑒 𝐶𝑂2 1 𝑚𝑜𝑙𝑒 𝐶3𝐻8 𝑥 44 𝑔 𝐶𝑂2 1 𝑚𝑜𝑙𝑒 𝐶𝑂2 = 30.0 grams of CO2

Name Period Home Work Sheet Chemical Reactions Start your Two-Week Homework Sheet Use the format shown to the right!!!!! Do Questions from Chapter 12: 80 Complete following questions: 77, 78, 79, 82,83 Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s

Chemical Reactions 11/8/2017 Substitute Work Sheet
To be handed in as part of your Homework Two Week Sheet Odd numbered tables do the odd numbered problems. Even numbered tables do the even numbered problems. For each of the assigned reactions on the opposite page, assume that 50 grams of the first reactant and 20 grams of the second reactant. Balance the chemical reaction equation. After identifying which reactant is the Limiting Reactant, circle the Limiting Reactant. After determining the mass of the second Product from the amount of the Limiting Reactant, write the mass (grams) of second product under the second product.

Carbon Dioxide is produced in the following combustion reaction if we start with 50.0 grams of propane and 1.00 grams oxygen? C3H8 + 5O2 → 4H2O + 3CO2 2.29 grams 1.67 grams 1.23 grams 0.825 grams

Percent Yield = Actual Yield(g)/Theoretical Yield(g) x 100%
Chemical Reactions 11/9/17 Write in Notebook Stoichiometry (Percent Yield) We can calculate the expected moles or mass (grams) of each product, theoretical yield. Generally, a chemical reaction does not produce 100% of the expected amounts. If we are given the actual amount, actual yield, of a product produced by a chemical reaction, then we can determine the percent yield. Percent Yield = Actual Yield(g)/Theoretical Yield(g) x 100% For example: (Do not write in notebook) When a solution of K2CrO4(aq) is added to a solution of AgNO3(aq), Ag2CrO4(s) precipitates out of solution. We can filter and collect the solid Ag2CrO4(s), dry it and weigh it to determine the actual amount precipitated. From that amount and the expected yield, we can calculate a percent yield.

Stoichiometry (Percent Yield) Example: A solution with 25g of K2CrO4(aq) are added to a solution with 25g of AgNO3(aq). 10g of Ag2CrO4(s) are collected. What is the Percent Yield? K2CrO4(aq) + 2AgNO3(aq) → Ag2CrO4(s) + 2KNO3(aq) 0.129moles 0.147moles moles Ratio: (LR) 24.4 grams % yield

Stoichiometry (Percent Yield) Example: A solution with 2.5g of K2CrO4(aq) are added to a solution with 25g of AgNO3(aq). 1.0g of Ag2CrO4(s) are collected. What is the Percent Yield? K2CrO4(aq) + 2AgNO3(aq) → Ag2CrO4(s) + 2KNO3(aq) moles 0.147moles moles Ratio: (LR) grams % yield

Name Period Home Work Sheet Chemical Reactions Start your Two-Week Homework Sheet Use the format shown to the right!!!!! Do Questions from Chapter 12: 85, 87, 90 Unit Test Next Friday. We will prepare for test all next week. Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s Date Assigned Problems. Complete sentences Show math, units, sig. figs. Highlight or box answers 2.5 m/s

Carbon Dioxide is produced in the following combustion reaction if we start with 50.0 grams of propane and 30.0 grams oxygen, then end up with 10.0g of carbon dioxide – what is the percent yield? C3H8 + 5O2 → 4H2O + 3CO2 82% 74% 40% 28%

Chemical Reactions 11/13/2017 CRAM Sheet for Test
CRAM Sheet for Unit 2 Test. Work on problems. We will do a learning game based on these questions Tuesday.

Chemical Reactions 11/14/2017 The Tile Game CRAM Sheet, Tile Game.
Your Table Groups will be your teams.. Person with highest grade is the score keeper. Team responds to each question posed with four answers. Answers can be all the same or split if there is not team agreement. Team with highest number of points at the end of the period wins a box of cookies to split.

Water is produced in the following combustion reaction if we start with 50.0 grams of propane and 30.0 grams oxygen, then end up with 10.0g of water – what is the percent yield? C3H8 + 5O2 → 4H2O + 3CO2 82% 74% 40% 28%

Chemical Reactions 11/15/2017 Vocabulary
Complete the Vocabulary Sheet for Unit 2.

Chemical Reactions 11/16/2017 Starter / Plicker Vocabulary Plicker 82%
74% 40% 28%

Chemical Reactions 11/16/2017 Review for Test General Review

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