Types of Chemical Reactions Combination Reactions aka Synthesis

Types of Chemical Reactions

Combination Reactions (aka Synthesis) = a chemical change in which 2 or more substances react to form a single new substance A + B AB +

Example: 2 K + Cl 2 2 KCl

Predict the products! Write and balance the following synthesis reaction equations: • Sodium metal reacts with chlorine gas Na(s) + Cl 2(g) • Solid Magnesium reacts with oxygen gas Mg(s) + O 2(g) • Aluminum metal reacts with fluorine gas Al(s) + F 2(g) http: //www. youtube. com/watc h? v=t. CH 3 oc. XPJw. Q&feature= related

Decomposition Reactions = a chemical change in which a single compound breaks down into 2 or more simpler products AB A + B +

Example: 2 Hg. O 2 Hg + O 2 http: //hogan. chem. lsu. ed u/matter/cha p 27/demos/d m 27_013. mo v

Predict the products! Write and balance the following decomposition reaction equations: • Solid Lead (IV) oxide decomposes Pb. O 2(s) Carbonates and chlorates are • Limestone decomposes Ca. CO 3 • Aluminum nitride decomposes Al. N(s) special case decomposition reactions that do not go to the elements: Carbonates (CO 32 -) decompose to carbon dioxide and a metal oxide Ex: Ca. CO 3 CO 2 + Ca. O Chlorates (Cl. O 3 -) decompose to oxygen gas and a metal chloride

GROUP WORK BREAK!: Dancing with Reactants http: //www. youtube. com/watch? v=j. Klxjbh. B 9 HE&e url=http: //video. google. com/videosearch? hl=en&q =dancing&um=1&ie=UTF 8&sa=X&oi=video_result_group&resnumiurl=http: //i 3. ytimg. com/vi/j. Klxjbh. B 9 HE/hqdefault. jpg

Single Replacement Reactions = a chemical change in which one element replaces a second element in a compound A + BC AC + B

Example: 2 Li + 2 H 2 O 2 Li. OH + H 2

Examples: 2 K + 2 H 2 O 2 KOH + H 2 Potassium replaces hydrogen in water to form potassium hydroxide and hydrogen gas. http: //www. youtube. com/watch? v=OFG 4 Yr 7 l. Qzw 2 Na + 2 HCl H 2 + 2 Na. Cl Sodium replaces hydrogen in hydrochloric acid to yield hydrogen and sodium chloride.

***Whether one metal will displace another metal from a compound depends on the relative reactivities of the 2 metals. *** (See Reference Tables: Table J) A reactive metal will replace any metal listed below it in the activity series. A reactive halogen will replace any halogen listed below it in the activity series.

Predict the products! Write and balance the following single replacement reaction equations: • Zinc metal reacts with aqueous hydrochloric acid Zn(s) + 2 HCl(aq) • Sodium chloride solid reacts with fluorine gas Na. Cl(s) + F 2(g) • Aluminum metal reacts with aqueous copper (II) nitrate Al(s)+ Cu(NO 3)2(aq)

Double Replacement Reactions = a chemical change involving an exchange of positive ions between 2 compounds AB + CD AD + CB + +

***For a double replacement reaction to occur, one of the following should be true: 1. ) One of the products is only slightly soluble and precipitates from solution. 2. ) One of the products is a gas. 3. ) One product is a molecular compound.

Examples: Mg. O + Be. S Mg. S + Be. O Oxygen and sulfur switch places to form magnesium sulfide and beryllium oxide. Na 2 S + Zn(NO 3)2 2 Na(NO 3) + Zn. S Sulfur and nitrate switch places to form sodium nitrate and zinc sulfide.

Predict the products! Write and balance the following double replacement reaction equations: 1. HCl(aq) + Ag. NO 3(aq) 2. Ca. Cl 2(aq) + Na 3 PO 4(aq) 3. Pb(NO 3)2(aq) + Ba. Cl 2(aq) 4. Fe. Cl 3(aq) + Na. OH(aq) 5. H 2 SO 4(aq) + Na. OH(aq) 6. KOH(aq) + Cu. SO 4(aq)

Combustion Reactions = a chemical change in which an element or compound (usually a hydrocarbon) reacts with oxygen - usually produces carbon dioxide and water http: //hogan. chem. lsu. edu/ma tter/chap 27/demos/dm 27_015. mov

Examples: • C 5 H 12 + O 2 CO 2 + H 2 O • 2 C 8 H 18 + 25 O 2 16 CO 2 + 18 H 2 O • 2 Mg + O 2 2 Mg. O • S + O 2 SO 2