Chemical Reactions Notes PDF

Chemical Reactions  1. Synthesis reactions Synthesis reactions occur when two substances (generally elements) combine and form a compound. (Sometimes these are called combination or addition reactions.) reactant + reactant 🡪 1 product Basically: A + B 🡪 AB...

Chemical Reactions  1. Synthesis reactions Synthesis reactions occur when two substances (generally elements) combine and form a compound. (Sometimes these are called combination or addition reactions.) reactant + reactant 🡪 1 product Basically: A + B 🡪 AB Example: 2H2 + O2 🡪 2H2O Example: C + O2 🡪 CO2  Synthesis Reactions Here is another example of a synthesis reaction  Practice Predict the products. Write and balance the following synthesis reaction equations. Sodium metal reacts with chlorine gas Na(s) + Cl2(g) 🡪 Solid Magnesium reacts with fluorine gas Mg(s) + F2(g) 🡪 Aluminum metal reacts with fluorine gas Al(s) + F2(g) 🡪  2. Decomposition Reactions Decomposition reactions occur when a compound breaks up into the elements or in a few to simpler compounds 1 Reactant 🡪 Product + Product In general: AB 🡪 A + B Example: 2 H2O 🡪 2H2 + O2 Example: 2 HgO 🡪 2Hg + O2  Decomposition Reactions Another view of a decomposition reaction:  Decomposition Exceptions Carbonates and chlorates are special case decomposition reactions that do not go to the elements. Carbonates (CO32-) decompose to carbon dioxide and a metal oxide Example: CaCO3 🡪 CO2 + CaO Chlorates (ClO3-) decompose to oxygen gas and a metal chloride Example: 2 Al(ClO3)3 🡪 2 AlCl3 + 9 O2 There are other special cases, but we will not discuss in Gr.10  Practice Predict the products. Then, write and balance the following decomposition reaction equations: Solid Lead (IV) oxide decomposes PbO2(s) 🡪 Aluminum nitride decomposes AlN(s) 🡪  Practice Identify the type of reaction for each of the following synthesis or decomposition reactions, and write the balanced equation: N2(g) + O2(g) 🡪 Nitrogen monoxide BaCO3(s) 🡪 Co(s)+ S(s) 🡪 (make Co be +3) NH3(g) + H2CO3(aq) 🡪 NI3(s) 🡪  3. Single Replacement Reactions Single Replacement Reactions occur when one element replaces another in a compound. A metal can replace a metal (+) OR a nonmetal can replace a nonmetal (-). element + compound🡪 product + product A + BC 🡪 AC + B (if A is a metal) OR A + BC 🡪 BA + C (if A is a nonmetal) (remember the cation always goes first!)  THE ACTIVITY SERIES Not every single-replacement reaction will happen. The element on the reactant side must be more “active” than the one it could replace. Scientists have listed the order of activity of elements in THE ACTIVITY SERIES.  Other Activity Series Information All metals will have a specific place in the activity series. For simplicity, only the most common metals are shown. The metals near the top of the activity series are more reactive because their valence electrons are more easily removed. Non-metals also have an activity series. We will only be using the 4 most common non-metals  Single Replacement Reactions Another view:  ACTIVITY SERIES non-metals Metals F2 Cl2 Br2 I2  Single Replacement Reactions Write and balance the following single replacement reaction equation: Zinc metal reacts with aqueous hydrochloric acid Zn(s) + 2 HCl(aq) 🡪 ZnCl2 + H2(g) Note: Zinc replaces the hydrogen ion in the reaction  Single Replacement Reactions Sodium chloride solid reacts with fluorine gas 2 NaCl(s) + F2(g) 🡪 2 NaF(s) + Cl2(g) Note that fluorine replaces chlorine in the compound Aluminum metal reacts with aqueous copper (II) nitrate Al(s)+ Cu(NO3)2(aq)🡪  4. Double Replacement Reactions Double Replacement Reactions occur when a metal replaces a metal in a compound and a nonmetal replaces a nonmetal in a compound Compound + compound 🡪 product + product AB + CD 🡪 AD + CB  Double Replacement Reactions Think about it like “foil”ing in algebra, first and last ions go together + inside ions go together Example: AgNO3(aq) + NaCl(s) 🡪 AgCl(s) + NaNO3(aq) Another example: K2SO4(aq) + Ba(NO3)2(aq) 🡪 2 KNO3(aq) + BaSO4(s)  Practice Predict the products. Balance the equation 1. HCl(aq) + AgNO3(aq) 🡪 2. CaCl2(aq) + Na3PO4(aq) 🡪 3. Pb(NO3)2(aq) + BaCl2(aq) 🡪 4. FeCl3(aq) + NaOH(aq) 🡪 5. H2SO4(aq) + NaOH(aq) 🡪 6. KOH(aq) + CuSO4(aq) 🡪  5. Combustion Reactions Combustion reactions occur when a hydrocarbon reacts with oxygen gas. This is also called burning!!! In order to burn something you need the 3 things in the “fire triangle”: 1) A Fuel (hydrocarbon) 2) Oxygen to burn it with 3) Something to ignite the reaction (spark)  Combustion Reactions In general: CxHy + O2 🡪 CO2 + H2O Products in combustion are ALWAYS carbon dioxide and water. (although incomplete burning does cause some by-products like carbon monoxide) Combustion is used to heat homes and run automobiles (octane, as in gasoline, is C8H18)  Combustion Reactions Edgar Allen Poe’s drooping eyes and mouth are potential signs of CO poisoning.  Combustion Example C5H12 + 8 O2 🡪 5 CO2 + 6 H2O Write the products and balance the following combustion reaction: C10H22 + O2 🡪  Mixed Practice State the type, predict the products, and balance the following reactions: 1. BaCl2 + H2SO4 🡪 2. C6H12 + O2 🡪 3. Zn + CuSO4 🡪 4. Cs + Br2 🡪 5. FeCO3 🡪