10826 AP Chemistry Chemical Equations Worksheet

(s) Solutions of silver nitrate and sodium chromate aremixed.2Ag + + CrO2–4→ Ag 2CrO 4(t) Glacial acetic acid is mixed with liquid methanol(nonaqueous).CH 3COOH + CH 3OH → CH 3COOCH 3+ H 2O(u) Chlorine gas is bubbled into a cold, dilute solution ofpotassium hydroxide.Cl 2+ 2OH – → ClO – + Cl – + H 2O(v) A strip of copper is immersed in a concentratednitric acid solution.Cu + 4H + + 2NO–3→ Cu 2+ + 2NO 2+ 2H 2O(w) Hydrogen gas is passed over hot iron(II) oxidepowder.H 2+ FeO → Fe + H 2O(x) Acidified potassium permanganate is added to asolution of sodium nitrite.2MnO–4+ 6H + + 5NO–2→2Mn 2+ + 3H 2O + 5NO–3(y) A solution of sodium bromide is added to an acidifiedsolution of potassium bromate.5Br – + 6H + + BrO–3→ 3Br 2+ 3H 2O(z) Aluminum metal is added to a solution of copper(II)chloride.2Al + 3Cu 2+ → 2Al 3+ + 3Cu(aa) Excess chlorine gas is passed over hot iron filings.3Cl 2+ 2Fe → 2FeCl 3(bb) Magnesium metal is added to nitrogen gas.3Mg + N 2→ Mg 3N 2What is the oxidation number of chromium in the chromateion?Answer: +6.What type of organic reaction can this becharacterized as?Answer: An esterification reaction.What element is undergoing oxidation and what elementis undergoing reduction?Answer: Chlorine, Cl, is being reduced to –1 (Cl – ) andalso being oxidized to +1 in ClO – .List at least two observations that indicate a chemicalreaction is occurring.Answer: Solution color changes from colorless to blue.Bubbles of NO 2gas are observed at the copperstrip. The gas is brown.What is the oxidation number of the hydrogen in hydrogengas?Answer: Zero—the oxidation number of an atom in itselemental form is zero.Write and balance the oxidation half-reaction for massand charge.Answer: H 2O + NO–2→ NO–3+ 2H + + 2e –Write and balance the reduction half-reaction for massand charge.Answer: 12H + + 2BrO–3+ 10e – → Br 2+ 6H 2OList at least two observations that indicate a chemicalreaction is occurring.Answer: The aluminum dissolves, a red solid precipitates,the blue color of the solution fades, andthe solution temperature increases.What type of reaction is occurring?Answer: A synthesis reaction (or a redox reaction).What is the oxidation number of magnesium before andafter the reaction?Answer: Magnesium goes from zero in Mg to +2 inMg 3N 2.– 7 –Publication No. 10826Your Safer Source for Science Supplies© 2007 Flinn Scientific, Inc. All Rights Reserved.(800) 452-1261 • Fax: (866) 452-1436 • P.O. Box 219 • Batavia, IL 60510 • E-mail: flinn@flinnsci.com • www.flinnsci.com