Chemistry: Chemical Equations

Transcription

1 Chemistry: Chemical Equations Write a balanced chemical equation for each word equation. Include the phase of each substance in the equation. Classify the reaction as synthesis, decomposition, single replacement, or double replacement.. Solid magnesium reacts with oxygen gas to yield solid magnesium oxide.. Solid aluminum reacts with a solution of lead (II) nitrate to yield solid lead and aqueous aluminum nitrate.. Solid diphosphorus pentoxide reacts with solid barium oxide to yield solid barium phosphate. 4. When heated, solid lead (IV) oxide breaks down into solid lead (II) oxide and oxygen gas. 5. A solution containing silver nitrate and potassium sulfate reacts to form a silver sulfate precipitate. The potassium nitrate that is formed remains in solution.. Solid sodium hydroxide decomposes into solid sodium oxide and liquid water. 7. Fluorine gas reacts with liquid water to form ozone gas and aqueous hydrofluoric acid. 8. Solid iron reacts with oxygen gas to yield solid iron (III) oxide. 9. Chlorine gas reacts with a solution of lithium iodide to form lithium chloride solution and iodine gas. 0. A solution of ammonium carbonate and lead (II) nitrate yields a solution of ammonium nitrate and a lead (II) carbonate precipitate.

2 Chemistry: Stoichiometry Balance the equations; then solve the following problems. Assume that excess amounts of other reactants are available, unless otherwise specified.. If 0.0 g of magnesium react with excess hydrochloric acid, what mass of magnesium chloride is produced? g(s) + HCl(aq) gcl (s) + H (g). How many dm of chlorine gas are needed (at STP) if 0.0 g of sodium chloride must be produced? NaI(aq) + Cl (g) NaCl(aq) + I (g). If 0.0 g of calcium hydroxide react with ammonium sulfate, how many molecules of ammonia are produced? (NH 4 ) SO 4 (aq) + Ca(OH) (s) CaSO 4 (s) + NH (g) + H O(l) 4. If 554 L of oxygen are consumed, how many kj of energy are released? C H O (s) + O (g) CO (g) + H O(l) kj 5. If.5 g of hydrochloric acid and 7.0 g of zinc are put together A. write a balanced chemical equation for this reaction. B. determine the limiting reactant. C. find the maximum volume of hydrogen gas formed at STP. D. determine the mass of excess reactant that is left over, if the reaction is 00% efficient. E. find actual volume of hydrogen produced at STP if the percent yield is 9.%.

3 Chemistry: Phase Changes and Calorimetry Solve each of the problems below. You may need to use some of the information given in the table. Acetic acid (CH COOH) c p =.05 J/g o C Aluminum c p = 0.89 J/g o C c f = 89 J/g c v = 0778 J/g Chalk (CaCO ) c p = 0.90 J/g o C Glass c p = 0.75 J/g o C Gold c p = 0.8 J/g o C c f = 5 J/g c v = 74 J/g Kerosene c p =.09 J/g o C Toluene (C H 5 CH ) c p =.80 J/g o C Find the change in energy when. 4. g of water condense at 00 o C.. 7. g of aluminum freeze at 0 o C g of gold melt at 04 o C g of acetic acid are heated from 4. o C to 7. o C g of toluene are heated from 9. o C to 75.0 o C...47 g of kerosene are heated from 7. o C to 4.7 o C g of chalk are cooled from 8. o C to 55.5 o C. 8.. g of glass are cooled from 95.5 o C to 4. o C g of water are heated from.0 o C to 40.0 o C. 0. If 00.0 g of 7 o C water are placed in an insulated flask, how many g of ice at 0 o C must be added so that the final temperature is 5.0 o C?

4 Chemistry: The Gas Laws Solve each of the problems below, showing your work and using proper units.. A sample of hydrogen has an initial volume of 75.0 cm and an initial temperature of 0.0 o C. If the temperature drops to 0.0 o C and the pressure remains constant, find the new volume.. A gas occupies 50.0 dm of space at 0.0 o C. To what temperature (in o C) must the gas be cooled for it to occupy dm?. At 5.0 o C and kpa, find the volume occupied by a 8 g sample of chlorine. 4. At 58 o C and an unknown pressure, a sample of oxygen has a volume of 4 ml. If the gas takes up 88 ml at STP, find the initial pressure, in atm. 5. At a certain temperature and pressure, chlorine molecules have an average velocity of 4 m/s. Find the average velocity of sulfur dioxide molecules under the same conditions.. Find the pressure of the confined gas, in mm Hg. 7. One sample of Xe in a.55 L container exerts a pressure of. atm. A second sample of Xe is confined into a.85 L container and exerts.4 atm of pressure. If these samples are placed together into a 9.75 L container, find the resulting pressure. 8. Propane burns according to the equation: C H 8 (g) + 5 O (g) CO (g) + 4 H O(g) If the sample of propane occupies L at 0 o C and under atm of pressure, how many grams of oxygen are needed to react with all of the propane?

5 Chemistry: Solutions Solve each of the problems below, showing your work and using correct units.. Calculate the molarity of the following solutions. A. 0.0 g of acetic acid (CH COOH) in 85 ml of solution B g of phosphoric acid (H PO 4 ) in.05 L of solution C kg of potassium hydroxide (KOH) in 4750 ml of solution. Calculate the number of liters of solution needed to make each of the following. A. a.00 solution using 80.0 g of sodium hydroxide (NaOH) B. a solution using 5 g of ammonium hydroxide (NH 4 OH) C. a.00 solution using g of nitric acid (HNO ). Calculate the mass of solute in the following solutions. A ml of.00 Na SO 4. 7H O solution B..500 L of 0.40 KH PO 4 solution C. 5,000 ml of 4.00 HCl solution 4. What volume of.50 H SO 4 can be made from 4.00 L of. H SO 4? 5. Given the balanced chemical equation: Al(s) + CuSO 4 (aq) Cu(s) + Al (SO 4 ) (aq) What volume of 0.5 CuSO 4 is required to completely react with 5 g of aluminum?

6 Chemistry: Equilibrium Answer each question below by writing SHIFT LEFT (or ), SHIFT RIGHT (or ), or NO SHIFT to indicate what happens to the equilibrium position when the indicated stress or condition change occurs.. For the balanced chemical equation: N (g) + H (g) NH (g) + energy remove NH (g) decrease pressure. For the balanced chemical equation: CO (g) + H (g) + energy CO(g) + H O(l) decrease temperature add a catalyst. For the balanced chemical equation: SO (g) + O (g) SO (g) + energy increase SO (g) concentration increase temperature 4. For the balanced chemical equation: CO (g) + C(s) + energy CO(g) increase temperature increase CO concentration 5. For the balanced chemical equation: N O 4 (g) + energy NO (g) decrease pressure remove N O 4 (g). For the balanced chemical equation: H (g) + Cl (g) HCl(g) + energy increase H (g) concentration increase pressure 7. For the balanced chemical equation: N (g) + O (g) + energy NO(g) decrease O (g) concentration add a catalyst 8. For the balanced equation: CO (aq) + NH (aq) NH CONH (aq) + H O(l) + energy remove NH CONH (aq) increase CO concentration increase temperature add a catalyst

7 Chemistry: Acids and Bases Solve each of the problems below, showing your work and using correct units.. Calculate the concentration of hydroxide ion in an aqueous solution in which the hydrogen ion concentration is.4 x 0. Then calculate the ph and poh, and tell whether the solution is an acid or a base.. Find the hydronium ion concentration in a water solution in the hydroxide ion concentration is 5. x 0 8. Then calculate the ph and poh, and tell whether the solution is an acid or a base.. Calculate the hydronium and hydroxide ion concentrations in a solution having a ph of 5.4. Also find the poh, and tell whether the solution is an acid or a base. 4. Calculate the concentration of a magnesium hydroxide solution, given that 99. ml of the basic solution is neutralized by 8.0 ml of a 0.5 solution of nitric acid. Assume 00% dissociation. 5. Calculate the number of milliliters of sulfuric acid required to neutralize L of 0.8 potassium hydroxide. Assume 00% dissociation.. Find the ph of a solution consisting of 0.00 g of H SO 4 that is dissolved in 7.8 L of solution. 7. If 95 ml of 5.8 x 0 5 lithium hydroxide solution are added to the solution of Question, find the new ph of the resulting mixture.

8 Chemistry: Final Exam Review Problems, Selected Answers Stoichiometry g gcl..9 dm Cl x 0 m cules NH 4..8 x 0 4 kj 5. B. HCl is LR C.. L H D. 40. g Zn E. 0. L H The Gas Laws. 7. cm. 7.7 o C. 5.8 L Cl 4..4 atm m/s atm 8..7 x 0 g O Solutions. A. 0.0 B C..4. A..00 L B.. L C. 0. L. A. 4 g B. 49 g C. 50 g L L Acids and Bases. [OH ] = 4. x 0 ph =. poh =.8 base. [H O + ] =.9 x 0 7 ph =.7 poh = 7.9 acid. [H O + ] =.48 x 0 [OH ] =.88 x 0 9 poh = 8.54 acid ml

9 Chemistry: Chemical Equations Write a balanced chemical equation for each word equation. Include the phase of each substance in the equation. Classify the reaction as synthesis, decomposition, single replacement, or double replacement.. Solid magnesium reacts with oxygen gas to yield solid magnesium oxide. g(s) + O (g) go(s) synthesis. Solid aluminum reacts with a solution of lead (II) nitrate to yield solid lead and aqueous aluminum nitrate. Al(s) + Pb(NO ) (aq) Pb(s) + Al(NO ) (aq) single replacement. Solid diphosphorus pentoxide reacts with solid barium oxide to yield solid barium phosphate. P O 5 (s) + BaO(s) Ba (PO 4 ) (s) synthesis 4. When heated, solid lead (IV) oxide breaks down into solid lead (II) oxide and oxygen gas. PbO (s) PbO(s) + O (g) decomposition 5. A solution containing silver nitrate and potassium sulfate reacts to form a silver sulfate precipitate. The potassium nitrate that is formed remains in solution. AgNO (aq) + K SO 4 (aq) Ag SO 4 (s) + KNO (aq) double replacement. Solid sodium hydroxide decomposes into solid sodium oxide and liquid water. NaOH(s) Na O(s) + H O(l) decomposition 7. Fluorine gas reacts with liquid water to form ozone gas and aqueous hydrofluoric acid. F (g) + H O(l) O (g) + HF(aq) single replacement 8. Solid iron reacts with oxygen gas to yield solid iron (III) oxide. 4 Fe(s) + O (g) Fe O (s) synthesis 9. Chlorine gas reacts with a solution of lithium iodide to form lithium chloride solution and iodine gas. Cl (g) + LiI(aq) LiCl(aq) + I (g) single replacement 0. A solution of ammonium carbonate and lead (II) nitrate yields a solution of ammonium nitrate and a lead (II) carbonate precipitate. (NH 4 ) CO (aq) + Pb(NO ) (aq) NH 4 NO (aq) + PbCO (s) double replacement

10 Chemistry: Stoichiometry Balance the equations; then solve the following problems. Assume that excess amounts of other reactants are available, unless otherwise specified.. If 0.0 g of magnesium react with excess hydrochloric acid, what mass of magnesium chloride is produced? X g gcl g(s) + HCl(aq) gcl (s) + H (g) g gcl 95. g gcl 0 g gcl 4. g g g gcl g g How many dm of chlorine gas are needed (at STP) if 0.0 g of sodium chloride must be produced? X dm NaI(aq) + Cl (g) NaCl(aq) + I (g) Cl NaCl Cl 0 g NaCl.9dm Cl 58.5 g NaCl mol NaCl Cl.4 dm Cl. If 0.0 g of calcium hydroxide react with ammonium sulfate, how many molecules of ammonia are produced? X m' c NH (NH 4 ) SO 4 (aq) + Ca(OH) (s) CaSO 4 (s) + NH (g) + H O(l) Ca( OH ) mol NH.0x0 m' c NH 0 g Ca( OH ) 4.87x0 74.g Ca( OH ) Ca( OH ) NH ' 4. If 554 L of oxygen are consumed, how many kj of energy are released? C H O (s) + O (g) CO (g) + H O(l) kj X kj O 870kJ 554 LO.8x0.4 LO mol O 5. If.5 g of hydrochloric acid and 7.0 g of zinc are put together A. write a balanced chemical equation for this reaction. B. determine the limiting reactant. HCl(aq) + Zn(s) ZnCl (aq) + H (g) HCl X mol HCl.5 g HCl. 0mol HCl.5 g HCl would only need 0.5 mol Zn Zn X mol Zn.0 g Zn. mol Zn 5.4 g Zn 7 HCl is LR C. find the maximum volume of hydrogen gas formed at STP. H.4 L H X L H HCl. L H mol HCl H D. determine the mass of excess reactant that is left over, if the reaction is 00% efficient. Have. mol Zn, use up 0.5 mol Zn 0. mol Zn is left over; convert to grams 5.4 g Zn X g Zn 0. mol Zn 40. g Zn Zn E. find actual volume of hydrogen produced at STP if the percent yield is 9.%. X L H.9. L H 0. 0 L H 4 kj m c NH

11 Chemistry: Phase Changes and Calorimetry Solve each of the problems below. You may need to use some of the information given in the table. Acetic acid (CH COOH) c p =.05 J/g o C Aluminum c p = 0.89 J/g o C c f = 89 J/g c v = 0778 J/g Chalk (CaCO ) c p = 0.90 J/g o C Glass c p = 0.75 J/g o C Gold c p = 0.8 J/g o C c f = 5 J/g c v = 74 J/g Kerosene c p =.09 J/g o C Toluene (C H 5 CH ) c p =.80 J/g o C Find the change in energy when. 4. g of water condense at 00 o C.. 7. g of aluminum freeze at 0 o C g of gold melt at 04 o C g of acetic acid are heated from 4. o C to 7. o C g of toluene are heated from 9. o C to 75.0 o C...47 g of kerosene are heated from 7. o C to 4.7 o C g of chalk are cooled from 8. o C to 55.5 o C. 8.. g of glass are cooled from 95.5 o C to 4. o C g of water are heated from.0 o C to 40.0 o C. 0. If 00.0 g of 7 o C water are placed in an insulated flask, how many g of ice at 0 o C must be added so that the final temperature is 5.0 o C?

12 Chemistry: The Gas Laws Solve each of the problems below, showing your work and using proper units.. A sample of hydrogen has an initial volume of 75.0 cm and an initial temperature of 0.0 o C. If the temperature drops to 0.0 o C and the pressure remains constant, find the new volume. 75cm 9 K V K V 7.cm. A gas occupies 50.0 dm of space at 0.0 o C. To what temperature (in o C) must the gas be cooled for it to occupy dm? 50dm 9K 400dm T T 80.7 K o 7.7. At 5.0 o C and kpa, find the volume occupied by a 8 g sample of chlorine. Cl kpa kpa V 8 g K 5. 8LCl 7.0 g Cl mol K 4. At 58 o C and an unknown pressure, a sample of oxygen has a volume of 4 ml. If the gas takes up 88 ml at STP, find the initial pressure, in atm. P 4mL atm 88mL P.4atm K 7 K 5. At a certain temperature and pressure, chlorine molecules have an average velocity of 4 m/s. Find the average velocity of sulfur dioxide molecules under the same conditions.. Find the pressure of the confined gas, in mm Hg. vso 7g vso 44 4m 4.g s L C m s 70mmHg 98. kpa 8mmHg 9 mmhg 0.kPa 7. One sample of Xe in a.55 L container exerts a pressure of. atm. A second sample of Xe is confined into a.85 L container and exerts.4 atm of pressure. If these samples are placed together into a 9.75 L container, find the resulting pressure.. atm.55 L 9.75 L.4 atm.85 L 9.75 L Pz Pz. 7atm 8. Propane burns according to the equation: C H 8 (g) + 5 O (g) CO (g) + 4 H O(g) If the sample of propane occupies L at 0 o C and under atm of pressure, how many grams of oxygen are needed to react with all of the propane? atm L n 0.08L atm 0K n 0. molch mol K 5mol O g O X g O 0. mol CH8.7x0 g O C H O 8 8

13 Chemistry: Solutions Solve each of the problems below, showing your work and using correct units.. Calculate the molarity of the following solutions. A. 0.0 g of acetic acid (CH COOH) in 85 ml of solution 0.5mol X mol 0 g 0.5 mol CHCOOH 0. 0 CHCOOH 0 g 0.85 L B g of phosphoric acid (H PO 4 ) in.05 L of solution X mol 0.5mol 49 g 0.5mol HPO HPO 98 g.05 L C kg of potassium hydroxide (KOH) in 4750 ml of solution.845 mol X mol 75 g.845 mol KOH. 4 KOH 5.g L. Calculate the number of liters of solution needed to make each of the following. A. a.00 solution using 80.0 g of sodium hydroxide (NaOH).0 mol X mol 80 g.0 mol NaOH.00 X L. 00 L 40 g X L B. a solution using 5 g of ammonium hydroxide (NH 4 OH). mol X mol 5 g. mol NH4 OH X L. L 5 g X L C. a.00 solution using g of nitric acid (HNO ).0 mol X mol g.0 mol HNO.00 X L 0. L g X L. Calculate the mass of solute in the following solutions. A ml of.00 Na SO 4. 7H O solution 8.g X mol 0.5 L 0.5mol X g 0.5mol 4 g NaSO4 7 HO B..500 L of 0.40 KH PO 4 solution X mol.g L 0.mol X g 0.mol 49 g KHPO C. 5,000 ml of 4.00 HCl solution.5 g X mol L 00 mol X g 00 mol 50 g HCl 4. What volume of.50 H SO 4 can be made from 4.00 L of. H SO 4?. 4 L.50 Vdilute Vdilute 9. 7 L 5. Given the balanced chemical equation: Al(s) + CuSO 4 (aq) Cu(s) + Al (SO 4 ) (aq) What volume of 0.5 CuSO 4 is required to completely react with 5 g of aluminum? X mol CuSO Al mol CuSO 5 mol CuSO 7 g Al mol Al 4 4 g Al mol X L 7. 8 L X L 4 4 4

14 Chemistry: Equilibrium Answer each question below by writing SHIFT LEFT (or ), SHIFT RIGHT (or ), or NO SHIFT to indicate what happens to the equilibrium position when the indicated stress or condition change occurs.. For the balanced chemical equation: N (g) + H (g) NH (g) + energy remove NH (g) decrease pressure SHIFT RIGHT SHIFT LEFT. For the balanced chemical equation: CO (g) + H (g) + energy CO(g) + H O(l) decrease temperature add a catalyst SHIFT LEFT NO SHIFT. For the balanced chemical equation: SO (g) + O (g) SO (g) + energy increase SO (g) concentration increase temperature SHIFT RIGHT SHIFT LEFT 4. For the balanced chemical equation: CO (g) + C(s) + energy CO(g) increase temperature increase CO concentration SHIFT RIGHT SHIFT LEFT 5. For the balanced chemical equation: N O 4 (g) + energy NO (g) decrease pressure remove N O 4 (g) SHIFT RIGHT SHIFT LEFT. For the balanced chemical equation: H (g) + Cl (g) HCl(g) + energy increase H (g) concentration increase pressure SHIFT RIGHT NO SHIFT 7. For the balanced chemical equation: N (g) + O (g) + energy NO(g) decrease O (g) concentration add a catalyst SHIFT LEFT NO SHIFT 8. For the balanced equation: CO (aq) + NH (aq) NH CONH (aq) + H O(l) + energy remove NH CONH (aq) increase CO concentration increase temperature add a catalyst SHIFT RIGHT SHIFT RIGHT SHIFT LEFT NO SHIFT

15 Chemistry: Acids and Bases Solve each of the problems below, showing your work and using correct units.. Calculate the concentration of hydroxide ion in an aqueous solution in which the hydrogen ion concentration is.4 x 0. Then calculate the ph and poh, and tell whether the solution is an acid or a base..4x0 ph OH log.4x0.8 x0 4. OH 4.x0 poh BASE. Find the hydronium ion concentration in a water solution in the hydroxide ion concentration is 5. x 0 8. Then calculate the ph and poh, and tell whether the solution is an acid or a base HO 5.x0 x0 HO.9x0 7 ph log.9x0.7 poh 7.9 ACID. Calculate the hydronium and hydroxide ion concentrations in a solution having a ph of 5.4. Also find the poh, and tell whether the solution is an acid or a base. 5.4 HO 0.48x0 poh 8.54 OH x0 ACID 4. Calculate the concentration of a magnesium hydroxide solution, given that 99. ml of the basic solution is neutralized by 8.0 ml of a 0.5 solution of nitric acid. Assume 00% dissociation. g(oh) g + + OH AND HNO H + + NO L OH 0.099L OH. 54 g OH Calculate the number of milliliters of sulfuric acid required to neutralize L of 0.8 potassium hydroxide. Assume 00% dissociation. H SO 4 H + + SO 4 AND KOH K + + OH.08 X L L X L 0.95 L 9. 5mL. Find the ph of a solution consisting of 0.00 g of H SO 4 that is dissolved in 7.8 L of solution. X mol 98.g.4x0 mol 7.8 L g.4x0 mol.77x0 HSO4 H.54x0 ph log.54x0 7. If 95 ml of 5.8 x 0 5 lithium hydroxide solution are added to the solution of Question, find the new ph of the resulting mixture. EXTRA OH x 0 mol HSO4 4.8x0 mol H X mol LiOH 5.8x L 5.54x0 mol LiOH 5.54x0 mol OH 8.5x0 mol 8. L 8.5x 0 mol OH OH.0x0 OH poh log.0x0 ph