Practice Packet Unit 3: Moles & Stoichiometry

Transcription

1 PRACTICE PACKET: Unit 3 Moles & Stoichiometry Regents Chemistry: Mr. Palermo Practice Packet Unit 3: Moles & Stoichiometry Vocabulary: Lesson 1: Lesson 2: Lesson 3: Lesson 4: Lesson 5: Lesson 6: Lesson 7: Lesson 8: Lesson 9: 1

2 PRACTICE PACKET: Unit 3 Moles & Stoichiometry For each word, provide a short but specific definition from YOUR OWN BRAIN! No boring textbook definitions. Write something to help you remember the word. Explain the word as if you were explaining it to an elementary school student. Give an example if you can. Don t use the words given in your definition! Mole: Molar Mass (gram formula mass): Reactants: Products: Coefficients (in reactions): Conservation of mass: Empirical Formula: Molecular Formula: Synthesis reaction: Decomposition reaction: Double replacement reaction: Single replacement reaction: Diatomic element: Polyatomic ion: Binary compound: Tertiary compound: Subscript: Superscript: Percent Composition: 2

3 PRACTICE PACKET: Unit 3 Moles & Stoichiometry LESSON 1: Moles and Molar Mass Objective: Calculate Molar Mass (gram formula mass) 1. Fill in the table below Formula a. HClO 3 Moles of each atom 1 mol of H atoms 1 mol of Cl atoms 3 mol of O atoms Total moles of atoms 5 mol of atoms Formula c. CaCl 2 Moles of each atom Total moles of atoms b. Mg(OH) 2 d. Mg 3(PO 4) 2 Calculate the gram formula mass (molar mass) and don t forget the units!!! 1. CO2 6. H2SO4 2. FeS 3. NaCl 7. Al2(SO3)3 8. C12H22O4 4. Al2(CO3)3 9. Fe2O3 5. SiO2 3

4 PRACTICE PACKET: Unit 3 Moles & Stoichiometry 12. CH4 10. MgO 13. NH3 11. Ca(OH)2 14. H2O2 ASSESS YOURSELF ON THIS LESSON: /14 If you missed more than 3, do the Additional Practice. If not, go on to the next hw video!!! ADDITIONAL PRACTICE LESSON 1: Find the gram formula mass of the following: (Show all work) 1. MgO 2. NaHCO3 3. C6H12O6 4. Al2O3 ASSESS YOURSELF ON THIS ADDITIONAL PRACTICE: /4 If you missed more than 1 you should see me for extra help and/or re-watch the lesson video assignment 4

5 Lesson 2: Calculating Moles Objective: Calculate the number of moles given the grams Calculate the number of grams given the moles Solve for the mass given the moles. (Show your work) moles of C6H12O moles of SiO moles of SrSO moles of FeS moles of CH moles of MgO moles of NH moles of ZnCl2 5

6 Find the number of moles in the following measurements: (Show your work) grams C6H12O grams of CO grams H2SO grams of Fe2O grams SiO grams of H2O grams of ZnCl grams of NaHCO3 ASSESS YOURSELF ON THIS LESSON: /14 If you missed more than 3, do the Additional Practice. If not, go on to the next hw video!!! ADDITIONAL PRACTICE LESSON 2 1. What is the total number of moles in 80.0 grams of C2H5? 2. How many grams are in moles of CH4? 3. How many grams are in moles of ZnCl2 4. What is the total number of moles in 10. grams of Fe2O3? ASSESS YOURSELF ON THIS ADDITIONAL PRACTICE: /4 If you missed more than 1 you should see me for extra help and/or re-watch the lesson video assignment 6

7 Lesson 3: Mole to Mole Ratios Objective: Calculate mole ratios in a chemical formula Use the formula below to answer questions 1-7 3Cu + 8HNO3 3Cu(NO3)2 + 2NO + 4H2O 1. If 1.00 mole of water is produced, how many moles of HNO3 are used? 2. If 1.50 moles of copper are used, how many moles of NO are produced? 3. If 4.50 moles of HNO3 are used, how many moles of copper (II) nitrate are produced? 4. If moles of NO are produced, how many moles of copper (II) nitrate produced? Use the formula below to answer questions 5-7 Fe2O3 + 3CO 2Fe + 2CO2 5. If 3.00 moles of Iron (III) oxide are used, how many moles of Iron are formed? 6. If 2.50 moles of CO are used, how many moles of carbon dioxide are formed? 7. If 8.56 moles of iron were produced, how many moles of the iron ore were used? 7

8 Challenge Problems: Use the formula below to answer questions Cu + 8HNO3 3Cu(NO3)2 + 2NO + 4H2O 8. If 9.00 grams of water are produced, how many moles of copper were used? 9. If 3.00 moles of copper are mixed with 4 moles of HNO3, how many moles of NO can be formed? 10. If 16.0 moles of HNO3 react with 4.00 moles of copper, how many moles of water are produced? ASSESS YOURSELF ON THIS LESSON: /10 If you missed more than 2, do the Additional Practice. If not, go on to the next hw video!!! ADDITIONAL PRACTICE LESSON 3: 1. Given the balanced equation: CaCO3(s) + 2HCl(aq) CaCl2(aq) + H2O(l) + CO2(g) What is the total number of moles of CO2 when 20. Moles of HCl is completely consumed? 2. Given the balanced equation: F2(g) + H2(g) 2HF(g) What is the total mole ratio of H2(g) to HF(g) in the reaction? ASSESS YOURSELF ON THIS ADDITIONAL PRACTICE: /2 If you missed any problems you should see me for extra help and/or re-watch the lesson video assignment 8

9 Lesson 4: Balancing Reactions Objective: Assess and Balance chemical reactions using coefficients 1. Which equation represents conservation of mass? (1) H2 + Cl2 HCl (2) H2 + Cl2 2HCl (3) H2 + O2 H2O (4) H2 + O2 2H2O 2. A 4.86-gram sample of calcium reacted completely with oxygen to form 6.80 grams of calcium oxide. This reaction is represented by the balanced equation below. Determine the total mass of Oxygen that reacted. 2Ca(s) + O2(g) 2CaO(s) BALANCE THE FOLLOWING REACTIONS 18. Challenge: Fe2O3 + CO Fe + CO2 9

10 Regents Practice 10

11 Types of Reactions Equation Reactant(s) Product(s) 27. Cl 2 + 2NaI 2NaCl + I 2 Cl2 and NaI NaCl and I2 Type of Reaction Single replacement 28. HNO 3 + LiOH H 2O + LiNO NaN 3 2Na + 3N Ba(NO 3) 2 + K 2SO 4 2KNO 3 + BaSO BaO + SO 3 BaSO Al + Fe 2O 3 Al 2O 3 + 2Fe 33. P 4 + 6Cl 2 4PCl CH 3OH (g)+3o 2(g) 2CO 2(g)+4H 2O (g) At your lab station, complete the following reactions below. Then determine what type of reactions is taking place. HCl(aq) + Zn(s) ZnCl2(aq) + H2(g) KI(aq) + PB(NO3)2(aq) KNO3(aq) + PbI2(aq) For each dark box define the word(s). Draw a particle diagram (model) to represent the phrase given. Then give a chemical symbol as an example in that box. Synthesis reaction: Synthesis Reaction Decomposition Reaction Decomposition reaction: Single replacement reaction: Single Replacement Double replacement Double replacement reaction: 11

12 ASSESS YOURSELF ON THIS LESSON: /62 If you missed more than 7, do the Additional Practice. If not, go on to the next hw video!!! ADDITIONAL PRACTICE LESSON 4 Balance the following reactions and identify the type of reaction: 1. NO + O2 NO2 2. Ag + S Ag2S 3. Cu(OH)2 CuO + H2O 4. KClO3 KCl + O2 5. Al + O2 Al2O3 6. CO + O2 CO2 Draw a particle model to represent one physical change and 1 chemical change using real examples. ASSESS YOURSELF ON THIS ADDITIONAL PRACTICE: /8 If you missed more than 2 problems, you should see me for extra help and/or re-watch the lesson video assignment 12

13 Lesson 5: Determining empirical and molecular formulas Objective: Determine the empirical formula from the molecular formula Determine the molecular formula from the empirical formula Below is a list of formulas. Write the empirical formula (if not already empirical) Formula Empirical formula (simplest ratio) Formula Empirical formula (simplest ratio) a. C 4H 10 g. NH 4NO 3 b. C 3H 6 h. C 11H 22O 11 c. N 2O 4 i. K 2S 2O 3 d. Na 2SO 4 j. S 2O 4 e. C 6H 10 k. CH 4 f. Al 2O 3 l. C6H12Cl2O2 Calculate the molecular formula from the empirical 1. What is the molecular formula of a compound that has a mass of 276 and an empirical formula of NO 2? 2. What is the molecular formula of a compound that has a mass of 56g and an empirical formula of CH2? 3. What is the molecular formula of a compound that has a mass of 51g and an empirical formula of HO? 4. What is the molecular formula of a compound that has a mass of 289g and an empirical formula of NH3? 13

14 5. What is the molecular formula of a compound with a mass of 760g and an empirical formula of Cr2O3? C 2H 4O 2 C 4H 8O 2 ASSESS YOURSELF ON THIS LESSON: /26 If you missed more than 4, do the Additional Practice. If not, go on to the next hw video!!! 14

15 ADDITIONAL PRACTICE LESSON 5 1. What is the molecular formula of a compound that has a mass of 126g and an empirical formula of SO2? 2. What is the molecular formula of a compound that has a mass of 248g and an empirical formula of NO3? 3. Determine the empirical formula of C6H12O6 ASSESS YOURSELF ON THIS ADDITIONAL PRACTICE: /3 If you missed any problems you should see me for extra help and/or re-watch the lesson video assignment 15

16 Lesson 6: Percent Composition Objective: Calculate Percent Composition Calculate Percent composition of a hydrate Determine the % composition of all elements in these compounds. Show all work! 1) ammonium sulfite Formula: (NH4)2SO3 Mass of N %N Molar mass Mass of H %H Mass of S Mass of O %S %O 2) aluminum acetate Formula: Al(C2H3O2)3 Mass of Al %Al Molar mass Mass of C %C Mass of H Mass of O %H %O 3) sodium bromide Formula: NaBr Mass of Na %Na Molar mass Mass of Br %Br Percent Composition of a Hydrate 4. Determine the percent by mass of water in the following hydrates. a. Na2CO3 10H2O (GFM = 286g) b. MgSO4 7H2O (GFM = 246 g) 16

17 c. Initial mass of hydrate: 9.5 g Final mass of anhydrous salt: 3.77 g d. Initial mass of hydrate: 5.3 g Final mass of anhydrous salt: 4.1 g 5. What is the percent composition of water in FeCl3. 6H2O? ASSESS YOURSELF ON THIS LESSON: /5 If you missed more than 1, do the Additional Practice. If not, go on to the next hw video!!! ADDITIONAL PRACTICE LESSON 6 1. copper (II) hydroxide Formula Cu(OH)2 Mass of Cu %Cu Molar mass Mass of O %O Mass of H %H 2. magnesium carbonate Formula: MgCO3 Mass of Mg %Mg Molar mass Mass of C %C Mass of O %O 3. If 125 grams of BaCl2. 2H2O is completely dehydrated, how many grams of anhydrous Barium Chloride will remain? ASSESS YOURSELF ON THIS ADDITIONAL PRACTICE: /3 If you missed any problems you should see me for extra help and/or re-watch the lesson video assignment 17

18 Lab Activity: Determining % Composition of a Hydrate Procedure: 1. Mass a crucible and cover. Mass of crucible and cover: 2. Add approximately 1.9 grams of the unknown hydrate to the crucible and record the actual mass of the crucible, hydrate and cover. Place the crucible and contents with cover on the triangle with the cover off centered. Mass of crucible, cover, and Hydrate: 3. Heat the crucible gently in the flame for 10 minutes. 4. Let the crucible and cover cool for one minute. Then, using tongs mass the crucible, cover and contents. Mass of crucible, cover, and product #1: 5. Re-heat the sample for one minute, cool and re-mass. Repeat this step until the mass remains constant. Mass of crucible, cover, and product #2: Mass of crucible, cover, and product #3: Questions: SHOW ALL WORK 1. Using YOUR DATA: a. Find the mass of the hydrate b. Find the mass of the anhydrate c. Find the mass of water lost. d. Convert the mass of the anhydrate CuSO4 to moles. 18

19 e. Convert the mass of water to moles. f. Divide the moles of water by the moles of anhydrate to find a whole number. This is the value of x in the formula CuSO4. xh2o. 2. Calculate the percent of water in your hydrate. 19

20 Lesson 7: Naming and Formula Writing for Binary Compounds Objective: Identify binary compounds by name Construct chemical formulas for binary compounds Ionic Compounds require two types of ions: cations which are positive and anions which are negative. All metals (on the left side of the periodic table) form cations and nonmetals (on the left side of the periodic table) form anions primarily. In order to determine the formula of the compound they create you must make sure their ions sum to zero. For example, table salt is sodium chloride. Using the periodic table s first set of ions, sodium forms +1 ions and chlorine forms -1 ions. Therefore their ions cancel out and the formula is NaCl. It is not always that easy. Calcium chloride is the salt we put on roads to melt ice. Calcium forms +2 ions and Chloride forms -1 ions. We need two chloride ions to balance the charges. The formula is CaCl2. Notice the metal, or positive cation is always written first! Try the following examples: 1. Cesium fluoride: 4. Barium sulfide: 2. Potassium oxide: 5. Aluminum chloride: 3. Magnesium iodide: 6. Calcium phosphide: There is a short cut called the drop and swap rule. Simply drop the charges from superscripts to subscripts and switch their order. In example 6 above, calcium phosphide had charges +2 and -3 respectively. Drop the charges to form uncharged subscripts 2 and 3 and reverse to form Ca3P2. Try the drop and swap rule to find the formula and don t forget to reduce if possible. Lithium Aluminum Chloride Sulfide Fluoride Phosphide AlCl3 Magnesium Zinc 20

21 Now we know how to write formulas from their names but we also need to know how to write names from formulas. The rule is: write the whole name of the first element and the second element drop the ending and replace with ide. For example: H2S is hydrogen sulfide. In this case, the amount of each element doesn t affect the name of the compound. Use table S to help you find names. Try to name the following examples: 1. NaF 6. NaH 2. MgCl2 7. K3P 3. Al2O3 8. MgO 4. MgI2 9. Li2Te 5. H2O 10. AlCl3 ASSESS YOURSELF ON THIS LESSON: /35 If you missed more than 5, do the Additional Practice. If not, go on to the next hw video!!! ADDITIONAL PRACTICE LESSON 7 Write the name of the following: 1. CaCl2 2. NaBr 3. NaS Write the chemical formula for the following: 4. zinc oxide 5. potassium bromide 6. Aluminum nitride ASSESS YOURSELF ON THIS ADDITIONAL PRACTICE: /6 If you missed more than 1 problem you should see me for extra help and/or re-watch the lesson video assignment 21

22 Lesson 8: Naming and Formula Writing with Multiple Oxidation States Objective: Identify binary compounds containing multiple charges by name using roman numerals Construct chemical formulas for binary compounds containing multiple charges If the first substance in a compound has more than 1 oxidation state you must write the charge used (roman numerals in parenthesis). Transition metals refer to the metals in groups 3-12 of the period table (elements Sc through Zn and down). These metals form various positive ions and therefore have more than one oxidation state (charge). It is important to identify which ion is used when naming the compound. We will work backwards to do this, meaning, we will look at the charge for the second ion in the formula to find that charge of the first. We will report the charge of the first ion in roman numerals (the numerals you need to memorize are listed to the right) in parenthesis after that ion. For example: One I Five V Two II Six VI Three III Seven VII Four IV CuO O is -2 so Cu needs to be +2 Copper (II) oxide Cu2O O is -2 so each Cu must be +1 Copper (I) oxide These two compounds have different structures and properties and must have different names. Try to name the following compounds with transition metals: 1. FeBr2 6. NiF3 2. FeBr3 7. CuCl 3. PbS 8. CuCl2 4. PbS2 9. CuS 5. NiO 10. Cu2S 22

23 Formula writing may seem easier. You can still use the drop and swap rule. Remember the number in roman numerals refers to the charge of the first ion. Try to give the formula of the following compounds: 1. Chromium (VI) oxide 6. Zinc (II) oxide 2. Manganese (VII) chloride 7. Iron (II) oxide 3. Lead (IV) iodide 8. Iron (III) oxide 4. Silver (I) sulfide 9. Gold (III) phosphide 5. Nickel (II) fluoride 10. Titanium (IV) sulfide ASSESS YOURSELF ON THIS LESSON: /35 If you missed more than 5, do the Additional Practice. If not, go on to the next hw video!!! ADDITIONAL PRACTICE LESSON 8 Write the name of the following: 1. FeCl 2 2. FeCl 3 3. Ag3N Write the chemical formula for the following: 4. copper (I) bromide 5. copper (II) bromide 6. Aluminum bromide ASSESS YOURSELF ON THIS ADDITIONAL PRACTICE: /3 If you missed any problems you should see me for extra help and/or re-watch the lesson video assignment 23

24 Lesson 9: Naming and Formula Writing Tertiary Compounds Objective: Identify tertiary compounds containing polyatomic ions by name Construct chemical formulas for tertiary compounds containing polyatomic ions Binary compounds have only two elements in their formula, as we saw in exercises above. Tertiary compounds have three or more elements in their formula and have a new system of naming. These compounds have a polyatomic ion, which is an ion that has a few elements grouped together with only one charge between them. A common example is OH - which shows two elements with an overall charge of -1. As before, name the first element completely and then look up the rest of the compound on table E of the reference tables. Make sure you copy the right one, some are very similar! For example: NaOH is called sodium hydroxide. Also, beware of NH4 + which is the only polyatomic cation (that comes in front). Try naming the following examples: 1. KHCO3 4. LiNO2 2. CaSO4 5. Cu(ClO4)2 3. NaNO3 6. Al2(SO3)3 To write the formula of a tertiary compound you can still use the drop and swap rule, however, you must be sure to only drop the superscripts and leave the subscripts alone. For example, aluminum carbonate: Al +3 and CO3-2 Leave the 3 alone! Swap the 3 and 2 Al2(CO3)3 Remember, formulas don t show any charges. You can see that we use parenthesis around the polyatomic ion because the entire ion charge was -2 and must swap with aluminum so the entire ion gets aluminum s 3. Try to write the formula for the following compounds (write the formulas of the ions next to the name first): Sodium Hydroxide Nitrate Carbonate Phosphate Acetate Calcium Ammonium Iron (II) Aluminum 24

25 1. Zinc Hydroxide: 4. Magnesium oxalate: 2. Calcium chlorate: 5. Lead (IV) chromate: 3. Hydrogen acetate: 6. Strontium cyanide: ASSESS YOURSELF ON THIS LESSON: /37 If you missed more than 6, do the Additional Practice. If not, go on to the next hw video!!! ADDITIONAL PRACTICE LESSON 9 Write the name of the following: 1. KNO3 2. LiOH 3. Ni(OH)2 Write the chemical formula for the following: 4. aluminum phosphate 5. strontium acetate 6. Aluminum sulfate ASSESS YOURSELF ON THIS ADDITIONAL PRACTICE: /6 If you missed any problems, you should see me for extra help and/or re-watch the lesson video assignment 25

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