Chemical Reactions

(10 days)

Dates	Topic(s)	Reading	Homework
10/10	Describing Chemical Reactions / Symbols / Law of Conservation of Matter Balancing Chemical Reactions	Word Equations/Chemical Equations, pp. 203 - 211	Supplemental Problems: 1 - 4
10/11	Types of Chemical Reactions	Types of Chemical Reactions, pp. 212 - 223	Section Review: 22 - 24, p 224 (#23 is hard! Try to find what type of reaction it is before trying to solve.) Concept Practice: 50, pp 232 - 233
10/12	Interpreting Balanced Reactions (molecules, moles, gas volumes, atoms, masses) Mathematics of Balanced Chemical Reactions: Mole Ratios	Using Everyday Equations, Interpreting Chemcial Equations, Mole-Mole Calcuations, pp 237 - 244	Section Review: 6 - 8, p 241 Supplemental Problems: 5 - 7
10/15	Mathematics of Balanced Chemical Reactions: The Mole Highway	Mass-Mass Calculations, Other Stoichiometric Calculations, pp 244 - 249	Section Review: 19 - 22, p 250
10/16	Practice Mole Highway Calculations	What is a Limiting Reagent, Calculating the Percent Yield, pp 252 - 258	Supplemental Problems 8 - 12
10/17	Limiting Reagents, % Yield	What is a Limiting Reagent, Calculating the Percent Yield, pp 252 - 258	Section Review: 29 - 32, p 259 Concept Review: 44 - 46 (a and b only), p 262
10/18	Limiting Reagents, % Yield		47, 51, 53, 54, p 263 (#47 is hard!--Do it last!)
10/19	Stoichiometry Wrap-Up Review	Chapter 8 and 9 Study Guides	Study!!
10/22	Hydrates, Anhydrates Desiccators, Nomenclature Unit 3 Test	Formula of a Hydrate Lab	Pre-Lab: Formula of a Hydrate
10/23	Formula of a Hydrate Lab		Write-Up: Formula of a Hydrate

Possible Labs: Formula of a Hydrate, Hardness of Water, Gram Molecular Weight of Citric Acid

Supplemental Problems:

1.	The equation for the reaction between nitric oxide, NO, and oxygen, O2, can be written: 2 NO + O2 2 NO2 (a) How many molecules of nitrogen dioxide, NO2, can be formed using two molecules of nitric oxide. (b) How many moles of nitric oxide are needed to give four moles of nitrogen dioxide? (c) How many moles of oxygen atoms are there in one mole of oxygen molecules? (d) How many moles of oxygen atoms are there in two moles of nitric oxide? (e) How many moles of oxygen atoms are there in two moles of nitrogen dioxide? (f) Use the answers to parts (c), (d), and (e) to verify that oxygen atoms are conserved in the reaction
2.	Write the equation for the reaction between nitrogen gas and hydrogen gas to give ammonia gas. The molecular formulas are N2, H2, and NH3 respectively. (a) Verify that your equation conserves nitrogen atoms. (b) Verify that your equation conserves hydrogen atoms.
3.	Balance the equation for each of the following reactions. Use only one mole of the underlined substance. (a) Li + Cl2 LiCl (b) Na + Cl2 NaCl (c) Na + F2 NaF (d) Na + Br2 NaBr (e) O2 + Cl2 Cl2O (f) O2 + Cl2 Cl2O Show that your answers to parts (e) and (f) contain the same information.
4.	Balance the equation for each of the following reactions involving oxygen. Use only ONE mole of the underlined substance. (a) Ni + O2 NiO (b) Ni + O2 NiO (c) Li + O2 Li2O (d) With the rocket fuel hydrazine, N2H4: N2H4 + O2 N2 + H2O (e) With the copper ore , Cu2S: Cu2S + O2 Cu2O + SO2 (f) With the iron pyrites (Fool's Gold), FeS2: FeS2 + O2 Fe2O3 + SO2
5.	When ammonia is decomposed into nitrogen gas and hydrogen gas. the reaction absorbs heat energy. The equation can be written this way: 2 NH3 + 22 kcal N2 + ? H2 (a) What coefficient should be placed in front of hydrogen gas to make a balanced reaction? (b) How many moles of nitrogen gas will be produced from two moles of ammonia? (c) How much heat energy would be absorbed during the production of one mole of nitrogen gas? (d) How much heat energy must be absorbed to produce nine moles of hydrogen gas? (e) Calculate the mass of two moles of ammonia. Compare that number with the sum of the masses of one mole of nitrogen gas and three moles of hydrogen gas. (f) Is this reaction endothermic or exothermic? (Endothermic means energy is absorbed while exothermic means energy is produced.)
6.	Answer the questions given the reaction at right: Al + CuCl2 AlCl3 + Cu (a) balance the reaction and use the balanced reaction to answer (b) - (e). (b) How many moles of copper (II) chloride would be required to react with 1 mole of Al? (c) How many moles of AlCl3 could be produced from 1 mole of Al? (d) Three moles of Al could produce how many moles of Cu? (e) Three moles of Al could produce how many grams of Cu?
7.	When iron rusts, it combines with oxygen in the air to form iron oxide, Fe2O3. Which of the following statements is FALSE? (a) The equation for the reaction is 3 O2 + 4 Fe 2 Fe2O3. (b) There are five atoms represented by the formula Fe2O3. (c) Atoms are conserved. (d) The mass of the reactants equals the mass of the products. (e) Molecules are conserved.
8.	Some hydrate is heated and decomposed to produce 0.151 grams of anhydrous salt and 0.090 grams of water. The molar mass of the anhydrous salt, MnSO4, is 151 grams. Which of the answers below is the formula of the hydrate? (Show work!) a) MnSO4* H2O b) MnSO4* 2H2O c) MnSO4* 3H2O d) MnSO4* 4H2O e) MnSO4*5H2O
9.	Balance and classify the following reactions as single displacement, double displacement, decomposition, synthesis, or combustion. (a) Al2(SO4)3 + KOH gives Al(OH)3 + K2SO4 (b) AlCl3 + LiH gives AlH3 + LiCl (c) Na + S8 gives Na2S
10.	Although sodium carbonate is needed in the manufacture of glass, very little sodium carbonate is found in nature. It is made using two very abundant chemicals, calcium carbonate (limestone) and sodium chloride. The process several steps. The overall reaction can be expressed this way: CaCO3 + 2 NaCl Na2CO3 + CaCl2 (a) What type of reaction is this? (b) If 10.0 g of CaCO3 were reacted with 10.0 g of NaCl, how much Na2CO3 would be produced? (c) Which reactant, CaCO3 or NaCl would remain at the end of the reaction? (d) What would be the mass of reactant left over?
11.	Compute the heat change (KJ) for the combustion of 1.24 grams of nitrogen monoxide to form NO2 according to the following equation: 2 NO (g) + O2 (g) 2 NO2 + 114.14 KJ
12.	Calculate the amount of energy given off when 17.0 g of iron (II) oxide reacts with 25.0 g of oxygen gas to form iron (III) oxide according the following reaction: 4 FeO + O2 2 Fe2O3 + 560.4 KJ a) What type of reaction is this? b) How much energy will be given off iff all the iron (II) oxide reacts? . . . all the O2 reacts? c) Use your answer to b) to decide which react will be left over at the end of the reaction. Can you figure out, how many grams of this reactant will remain? (Try it!)

 

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