1985
(a) Sodium metal is added to water.
1. Is this reaction exothermic or endothermic?
2. What color will any flame be when this reaction occurs?
(b) Dilute sulfuric acid is added to a solution of lithium hydrogen carbonate.
1. What visual evidence do we have that this reaction is occurring?
2. What is the oxidation number of sulfur in sulfuric acid?
(c) Ethanol and formic acid (methanoic acid) are mixed and warmed.
1. Is methanoic acid a weak acid or a strong acid?
2. What substance could be added to reverse this reaction?
3. What substance should be removed from this reaction to drive it to completion?
4. Will ethanol and methanoic acid be miscible? Justify your answer.
(d) Excess concentrated potassium hydroxide solution is added to a precipitate of zinc hydroxide.
1. What color is the zinc hydroxide precipitate?
2. How could one reverse the reaction in the problem?
(e) The gases boron trifluoride and ammonia are mixed.
1. Which reactant is capable of hydrogen bonding?
2. Which reactant is an acid and which is a base?
(f) A solution of tin(II) chloride is added to a solution of iron(III) sulfate.
1. Would a reaction with iron(III) phosphate be slower or faster? Why?
(g) Phosphorus(V) oxytrichloride is added to water.
1. Is this a redox reaction or an acid-base reaction?
2. If the reaction is an acid-base reaction, tell the base, if it is a redox reaction, tell the reducing agent.
(h) An acidified solution of sodium permanganate is added to a solution of sodium sulfite.
1. What color is the permanganate?
1986
(a) A piece of lithium metal is dropped into a container of nitrogen gas.
1. What will be observed as this reaction proceeds?
2. How could this reaction be reversed?
(b) Dilute hydrochloric acid is added to a solution of potassium sulfite.
1. Name any strong acids involved in this process.
2. Name any weak acids involved in this process.
3. Name any strong bases involved in this process.
4. Name any weak bases involved in this process.
5. Give a conjugate acid-base pair in this process.
(c) Solid sodium oxide is added to water.
1. Will the pH of the water increase or decrease?
(d) A solution of sodium sulfide is added to a solution of zinc nitrate.
1. What will be observed in this reaction?
(e) A solution of ammonia is added to a dilute solution of acetic acid.
(f) A piece of iron is added to a solution of iron(III) sulfate.
1. Name the oxidizing and reducing agents in this reaction.
2. What will happen to the piece of iron over the course of the reaction?
3. What can be done to the iron to speed up the reaction?
(g) Ethene (ethylene) gas is bubbled through a solution of bromine.
1. What is the appearance of the solution at the beginning of the reaction? What happens to its appearance as the reaction proceeds?
(h) Chlorine gas is bubbled into a solution of potassium iodide.
1. Describe the color change that occurs over the course of this reaction.
2. Name the oxidizing and reducing agents in the reaction.
1987
(a) Solid calcium is added to warm water.
1. Why is the water in the reaction warmed?
2. What visual evidence that a reaction is occurring can be seen in this process?
(b) Powdered magnesium oxide is added to a container of carbon dioxide gas.
(c) Gaseous hydrogen sulfide is bubbled through a solution of nickel(II) nitrate.
1. How can the products of this reaction be separated?
(d) Excess concentrated sodium hydroxide solution is added to solid aluminum hydroxide.
1. What is the oxidation number of the aluminum on the products side of the equation?
(e) Solid silver is added to a dilute nitric acid (6M) solution.
1. What color gas will be observed when this reaction is performed in a lab?
(f) Excess potassium hydroxide solution is added to a solution of potassium dihydrogen phosphate.
g) Hydrogen peroxide solution is added to a solution of iron(II) sulfate.
1. What visual evidence that a reaction is occurring can be seen in this process?
h) Propanol is burned completely in air.
1. Is propanol miscible in water? If yes, why, and if not, why not?
1988
(a) A solution of potassium iodide is added to an acidified solution of potassium dichromate.
1. What color change would be observed in the course of this reaction?
(b) A solution of sodium hydroxide is added to a solution of ammonium chloride.
1. What visual evidence that a reaction is occurring can be observed in this process?
(c) A strip of magnesium is added to a solution of silver nitrate.
1. What happens to the magnesium strip as the reaction proceeds?
2. Will the reaction be faster or slower with silver chloride substituted for the silver nitrate?
(d) Solid potassium chlorate is heated in the presence of manganese dioxide as a catalyst.
(e) Dilute hydrochloric acid is added to a solution of potassium carbonate.
1. What visual evidence that a reaction is occurring can be seen in this process?
(f) Sulfur trioxide gas is added to excess water.
1. What is the oxidation state of sulfur in the product?
(g) Dilute sulfuric acid is added to a solution of barium chloride.
1. Will the same type of reaction occur if magnesium chloride is substituted for the barium chloride?
(h) A concentrated solution of ammonia is added to a solution of copper(II) chloride.
1. Describe what this reaction looks like as it proceeds.
1989
(a) Solutions of zinc sulfate and sodium phosphate are mixed.
1. What visual evidence that a reaction is occurring can be seen in this process?
(b) Solutions of silver nitrate and lithium bromide are mixed.
1. How can the products of this reaction be separated?
(c) A stream of chlorine gas is passed through a solution of cold, dilute sodium hydroxide.
1. What is the oxidation state of chlorine in the reactants? In the products?
(d) Excess hydrochloric acid solution is added to a solution of potassium sulfite.
1. Give one conjugate acid-base pair in this reaction.
(e) A solution of tin(II) chloride is added to an acidified solution of potassium permanganate.
1. What is the oxidation state for manganese in the reactants? In the products?
(f) A solution of ammonium thiocyanate is added to a solution of iron(III) chloride.
(g) Samples of boron trichloride gas and ammonia gas are mixed.
1. Which reactant is a Lewis acid?
(h) Carbon disulfide vapor is burned in excess oxygen.
1990
(a) Solutions of sodium iodide and lead nitrate are mixed.
(b) A solution of ammonia is added to a solution of ferric chloride.
1. What are two names (besides reactant) one could use for ammonia in this reaction?
(c) A solution of hydrogen peroxide is heated.
(d) Solutions of silver nitrate and sodium chromate are mixed.
(e) Hydrogen sulfide gas is bubbled through a solution of potassium hydroxide.
(f) Solid dinitrogen pentoxide is added to water.
(g) A piece of solid bismuth is heated
(h) A strip of copper metal is added to a concentrated solution of sulfuric acid.
1991
(a) Solid aluminum oxide is added to a solution of sodium hydroxide.
(b) Solid calcium oxide is heated in the presence of sulfur trioxide gas.
(c) Equal volumes of 0.1-molar sulfuric acid and 0.1-molar potassium hydroxide are mixed.
(d) Calcium metal is heated strongly in nitrogen gas.
(e) Solid copper(II) sulfide is heated strongly in oxygen gas.
(f) A concentrated solution of hydrochloric acid is added to powdered manganese dioxide and gently heated.
(g) A concentrated solution of ammonia is added to a solution of zinc iodide.
(h) A solution of copper(II) sulfate is added to a solution of barium hydroxide.
1992
(a) An excess of sodium hydroxide solution is added to a solution of magnesium nitrate.
(b) Solid lithium hydride is added to water.
(c) Solutions of ammonia and hydrofluoric acid are mixed.
(d) A piece of aluminum metal is added to a solution of silver nitrate.
(e) A solution of potassium iodide is electrolyzed.
1. Which substance is oxidized in this reaction?
2. How many moles of electrons are transferred per mole of reduced substance?
(f) Solid potassium oxide is added to water.
(g) An excess of nitric acid solution is added to a solution of tetraaminecopper(II) sulfate.
1. What color change is observed over the course of this reaction?
2. How could this reaction be reversed?
(h) Carbon dioxide gas is bubbled through water containing a suspension of calcium carbonate.
1993
(a) A strip of copper is immersed in dilute nitric acid.
1. What is the color of the resulting solution in this process?
2. What is the oxidation state of the N in nitric acid. What is its change in oxidation state over the course of the reaction?
(b) Potassium permanganate solution is added to an acidic solution of hydrogen peroxide.
1. What is the change in oxidation state for the oxygen in the reaction?
(c) Concentrated hydrochloric acid is added to an acidic solution of hydrogen peroxide.
(d) Excess chlorine gas is passed over hot iron filings.
(e) Water is added to a sample of solid magnesium nitride.
1. What evidence that a reaction is occurring would a student performing this reaction have?
(f) Excess sulfur dioxide gas is bubbled through a dilute solution of potassium hydroxide.
(g) Excess concentrated ammonia solution is added to a suspension of silver chloride.
(h) Solutions of tri-potassium phosphate and zinc nitrate are mixed.
1. What evidence of reaction will be observed in this process?
1994
(a) Excess sodium cyanide solution is added to a solution of silver nitrate.
(b) Solutions of manganese(II) sulfate and ammonium sulfide are mixed.
1. What two gases could be mixed to produce the ammonium sulfide needed for this reaction?
(c) Phosphorous(V) oxide powder is sprinkled over distilled water.
(d) Solid ammonium carbonate is heated.
(e) Carbon dioxide gas is bubbled through a concentrated solution of potassium hydroxide.
(f) A concentrated solution of hydrochloric acid is added to solid potassium permanganate.
(g) A small piece of sodium metal is added to distilled water.
(h) A solution of potassium dichromate is added to an acidified solution of iron(II) chloride.
1995
(a) Ethanol is burned in oxygen.
(b) Solid barium oxide is added to distilled water.
(c) Chlorine gas is bubbled into a cold, dilute solution of potassium hydroxide.
(d) A solution of iron(II) nitrate is exposed to air for an extended period of time.
(e) Excess concentrated sulfuric acid is added to solid calcium phosphate.
(f) Hydrogen sulfide gas is bubbled into a solution of mercury(II) chloride.
(g) Solid calcium hydride is added to distilled water.
1. What is the oxidation state of the hydrogen in calcium hydride?
(h) A bar of zinc metal is immersed in a solution of copper(II) sulfate.
1. What will be observed as the reaction proceeds?
1996
(a) Solid calcium carbonate is strongly heated.
1. Would this reaction work better at high pressure or low pressure? Why?
(b) A piece of nickel metal is immersed in a solution of copper(II) sulfate.
(c) Equal volumes of equimolar solutions of disodium hydrogen phosphate and hydrochloric acid are mixed.
(d) Chlorine gas is bubbled into a solution of sodium bromide.
1. What will be observed as the reaction proceeds?
(e) Ammonia gas is bubbled into a solution of ethanoic (acetic) acid.
(f) Solid ammonium carbonate is added to a saturated solution of barium hydroxide.
(g) Drops of liquid dinitrogen trioxide are added to distilled water.
(h) Solutions of potassium permanganate and sodium oxalate are mixed.
1997
(a) Excess potassium hydroxide solution is added to a solution of aluminum nitrate.
(b) A solution of sodium bromide is added to an acidified solution of potassium bromate.
(c) Sulfur dioxide gas is bubbled into distilled water.
(d) Phosphine (phosphorus trihydride) gas is bubbled into liquid boron trichloride.
(e) Hydrogen gas is passed over hot iron(II) oxide powder.
(f) Solid potassium amide is added to distilled water.
(g) A strip of magnesium metal is heated strongly in pure nitrogen gas.
(h) A solution of nickel chloride is added to a solution of sodium sulfide.
1998
(a) Solutions of tin(II) chloride and iron(III) chloride are mixed.
(b) Solutions of cobalt(II) nitrate and sodium hydroxide are mixed.
(c) Ethene gas is burned in air.
(d) Equal volumes of equimolar solutions of phosphoric acid and potassium hydroxide are mixed.
(e) Solid calcium sulfite is heated in a vacuum.
(f) Excess hydrochloric acid is added to a solution of diamminesilver(I) nitrate.
1. What evidence that a reaction is occurring will be observed in this reaction?
(g) Solid sodium oxide is added to distilled water.
(h) A strip of zinc is added to a solution of 6.0-molar hydrobromic acid.
1. What evidence would one have that this reaction is occurring?
2. Would this reaction be faster, slower or the same rate with 6.0M hydrochloric acid substituted?