STOICHIOMETRY CLASSWORK

Transcription

1 STOICHIOMETRY CLASSWORK Given the following equation: 2 C4H > 8 CO H20 Show what the following molar ratios should be. a, C4H10 / 02 b. 02 / CO2 o, 02 / H20 d, C4Hlo / CO2 e. C4Hlo / H20 2. Given: Mg + 02 ÿ MgO a, Howmmw moles of oxygen will react with one mole of magnesium? b. How many moles of oxygen will react with two moles of magnesium? c, How many moles of MgO will be produced when 5 moles of magnesium react? 3. Given the following equation: Cu + 2 AgNO3 ---> Cu(NO3)2 + 2 Ag How many moles of Cu are needed to react with 3,50 moles of AgNOa? 4. Given the following equation: 2 KC > 2 KC How many moles of 02 can be produced by letting 12,00 moles of KC1O3 react? 5. Given the following equation: 2 K + C12 ---> 2 KC1 How many grams ofkc1 m'e produced fi'om 2.50 g of K? 6. Given the following equation: 8 Fe + $8 ---> 8 FeS What mass of iron is needed to react with 16,0 grams of sulfm'? How many grams of FeS are produced? 7. Given the following equation: 2 NaCIO3 ---> 2 NaC ,00 moles ofnac103 will produce how many grams of O2? I

2 STOICHIOMETRY PRACTICE PROBLEMS (LEVEL 2), When aluminum is heated in oxygen, aluminum oxide is formed. What weight of the aluminum oxide can be obtained from 25.0g of the metal? 2.' When steam (hot water) is passed over iron, hydrogen gas and iron (111) oxide are formed. What weight of steam would be needed to react completely with lo0.og of iron? 3. How much ammonium hydroxide is needed to react completely with 75.0g of copper (11) nitrate in a double replacement reaction? 4. When ammonia is burned in oxygen, free nitrogen gas and water are produced. What volume of ammonia will react completely with 25.0L of oxygen? What volume of nitrogen gas is formed?. When sodium carbonate reacts with hydrochloric acid, the carbonic acid that is formed immediately breaks down into carbon dioxide and water. What mass of sodium carbonate would have been present originally if 5.0 L of carbon dioxide were obtained in this way? 6. How much copper metal can be obtained by the single replacement reaction between copper (I) nitrate and 30.Og of iron metal? (Iron (11) nitrate is formed) 7, What weight of sulfuric acid will be needed to react completely with 35.5g of ammonia in the production of ammonium sulfate? 8. What mass of chlorine gas will be needed to react completely with 85.5g of Potassium iodide in a single replacement reaction? 9. In the neutralization reaction between sulfuric acid and potassium hydroxide, how much potassium sulfate can be produced if you have 150.0g of sulfuric acid to begin with? 10. What volume of nitrogen gas is needed to react completely with 150.0L of hydrogen in the production of ammonia?

3 More Fun with Stoichiometry #1 Cesium hydroxide decomposes into cesium oxide and water, a). Write the balanced equation for the reaction b). What amount of water is formed If 19.2 g of cesium hydroxide is used? 2ÿ Potassium hydroxide reacts with hydrobromlc acid. a). Write the balanced equation for the reaction, b), What mass of potassium hydroxide Is needed to completely react with 4,72 g of hydrobromio acid? c). Classify this reaction as single, double displacement, decomposition, synthesis or combustion, 3. 16,6 g of magnesium carbonate reacts with hydrochloric acid, What mass of carbon dioxide Is produced? 4. if 28,8 g of Na2SI03 is used, what mass of H2SiFB Is prodllced? Na2SiOÿ(s) + 8HF(.q) ÿ H2SIF6(.q). 2NaF(.q) + 3H20(i) 5, 19.3 g of C8H8 is burned in oxygen. What mass of oxygen is consumed? 6, What volume of hydrogen gas at STP is produced when 10,98 g of aluminum reacts with excess sulfuric acid? 7, 2,06 liters of oxygen gas at STP were produced from the decomposition of sodium chlorate. What mass of sodium chlorate decomposed? 8. The burning of propane (C3H8), Produces carbon dioxide and water vapor, What volume of propane will burn in 29.8 liters of oxygen? 9, 11,6 g of potassium reacts with excess hydrochloric acid, What mass of hydrogen gas Is produced? What type of reaction is this? (Single, Double, Synthesis, Decomposition, Combustion)

4 Even More Fun with Stoichiometry # g of sodium carbonate reacts with sulfuric aoid, What mass of carbon dioxide Is produced? 2, If 10.2 g of Na2SlO31s used, what mass of NaF Is produced? Na28103(ÿ) + 8HF(aq) ÿ H2SIF6(ÿq} + 2 NaF(.q) + 3H20(i) 3, 16,8 g of CÿH8 is burned in Oxygen, What mass of oxygen reacts? 4, What volume of hydrogen gas at 8TP is produced when 18,59 g of alumlnum reacts with excess sulfuric acid? 5, 2,96 liters of oxygen gas at STP were produced from the decomposition of potassium chlorate. What mass of potassium chlorate decomposed? 6. The burning of ethane, C2He, produces carbon dioxide and water vapor, What volume of ethane wltl burn in 24.8 liters of oxygen? 7, If 5,07 g of C2H ÿ is used in the following reaction, what mass of water Is produced? 2C2H , 4CO2 + 6HÿO g of aluminum reacts with excess hydrochloric acid. Write the balanced equation for the reaction, then determine the mass of hydrogen gas produced in the reaction and state what type of reaction it is,

5 More Fun with Stoichiometric Problems: Limiting Reactant. The reaction between solid white phosphorus (P4) and oxygen produces solid tetraphosphorus decoxide. A) Write the balanced chemical equation, B) Determine the mass of tetraphosphorus decoxlde formed If 25.0 g P4 (solid)and 50.0 g 02 are combined. C) How much excess reactant remains afterthe reaction stops? g The reaction between solid sodium and Iron (111) oxide Is one In a series of reactions that inflates a car alrbag, 6 Na(s) + Fe20ÿ (s) "-> 3Na20(s) + 2Fe(s) If g Na and g Fe203 are used in the reaction, determine the A) Limiting Reactant B) Reactant in excess C) Mass of solid Fe produced D) The mass of excess reactant that remains after the reaction ts complete 3, Photosynthesis reactions in green plants use C02 and water to produce glucose (C6H1206) and 02. A) Write the balanced chemical equation, If the plant has C02 and 64,0 g of H20 available for photosynthesis, determine B) The limiting reactant C) The excess reactant and the mass in excess D) The mass of glucose produced

6 % yield = Percent Yield actual yteld (from experiment) theoretical yield (from calculations) 1) A) Aluminum hydroxide is often present In antacids to neutralize stomach acid (HCI), Write a balanced equation for this reaction, B) If ::L4,0 g of aluminum hydroxide is present in an antacid tablet, determine the theoretical yield of alumlnum chloride produced when the tablet reacts with stomach acid, If the actual yield of aluminum chloride from this tablet Is 22,0 g, what Is the percent yield? 2) A) Zinc reacts with iodine In a synthesis reaction, Write a balanced equation for this reaction. B) Determine the theoretical yield if g of Zn was used. C) Determine the percent yield If g product Is recovered, 3) A) When Cu wire Is placed Into sliver nitrate solution, sliver crystals and copper (11) nitrate solution form, Write a balanced equation for this reaction, B) If 20.0 g sample of Cu is used, determine the theoretical yield of Ag. C) If 60.0 g of Ag Is actually recovered from the reaction, determine the % yield.

7 Show all work - balanced equation etc! Limiting Reagents 1) 100,0 grams of a mixture of sodium chloride and potassium nitrate are allowed to react, In excess and by how much? Which reactant is 2) 75 grams of potassium hydroxide are permitted to react with 50,0 grams of hydrochloric acid, How much potassium chloride ls formed? 3) 120,0 grams of sulfuric acid are added to 230,0 grams of barium peroxide, Which reactant Is In excess and by how much? How much barium sulfate is precipitated in this reaction? 4) 10.0 grams of hydrogen and 75 grams of oxygen are exploded together in a reaction tube, Besides water vapor, what other gas is found In the tube after the reaction, and how much of this gas is there? How much water is produced? 5) 50,0 grams of oxygen are available for the synthesis with 25 grams of carbon, Is this an adequate amount? If so, by how much in excess is the oxygen? If not, by how much is the carbon in excess? 6) 75,0 grams of zinc are added to 120 grams of sulfuric acid, How much hydrogen gas Is evolved? 7) What is the mass of aluminum oxide that Is produced from the reaction of 8,27 grams of manganese dioxide and 1,08 grams of AI? 3MnO2(s) + 4Al(s)-> 3 Mn(s) + 2AI203(s) 8) Given the reaction CaOO3(s) -> CaO(s) + CO2(g), If 50,0 grams of CaCOÿ reacts to produce 20,0 grams of CO2, what is the percent yield of CO2? 9) Given the reaction C6H6(I) + Cl2(g) "-> C6HÿOl(s) + HOl(g), when 36.8 grams of 08H6 reacts with an excess of 012, the actual yield of C6H6CI is 38.8 grams. What Is the percent yield? 10) If ammonia reacts according to the following equation, how many kilograms of NO could be produced from 10,0 kilograms of NH3 if the percent yield of NO is 80.0%? 4NH3(g) + 502(g)-> 4NO(g) + 6H20(g)

8 Stoichiometry Reviewsheet 1. Consider the reaction of magnesium with nitrogen gas to answer the next 5 questions. a) What information can we get from the reaction in terms of particles? Moles? b) If you have 6 mol magnesium and 5 mol nitrogen, what is the limiting reactant? c) If you have 5 moles of each reactant, how many moles of the excess reactant will be left over? d) If I react 210 kg of magnesium with excess nitrogen, what mass of magnesium nitride is formed? e) Determine the volume of nitrogen at STP necessary to produce 532 g of magnesium nitride. (assume excess magnesium) m How many milligrams of nickel chloride were in a solution if 503 mg of silver chloride are precipitated by the reaction of nickel chloride with excess silver nitrate?, What is the percent yield if 4.65 g of copper is produced when 1.87 g of aluminum reacts with excess copper(ii) sulfate?, Copper(I) sulfide is produced by reacting copper metal with sulfur in the presence of heat. a) What is the limiting reactant when 80.0 g of copper reacts with 25.0 g S? b) If you have 92% yield, what mass of copper sulfide was actually formed? c) What is the mass of the excess reactant left over?. The first step in the Ostwald process for manufacturing nitric acid is the reaction between ammonia and oxygen described by the reaction below: NH3 + O2-ÿ NO + H20 a) How many moles of ammonia will react with 49.6 mol of oxygen? b) If the reaction consumes 37.8 mol of ammonia, what mass of water will be produced? c) How many liters of ammonia gas (at STP) are required to produce 307 g of NO?. Determine the mass of butane gas (C4H10) that can be combusted with 31.8 L of oxygen at STP.. Solid zinc reacts with sulfuric acid and produces 0.1 g of hydrogen gas (and?). a) How many moles of zinc reacted? b) How many atoms of zinc reacted? c) What mass of zinc reacted?, In preparing a paint pigment of chrome yellow (lead(ii) chromate), a student used 6.94 g of lead(ii) nitrate and an excess of sodium chromate. Determine the a) theoretical yield b) the percent yield if 6.44 g of lead(ii) chromate was produced, How many moles of aluminum oxide are produced when 6 moles of aluminum are combined with excess oxygen? How many molecules of oxygen are needed to react with 6 moles of aluminum?