Chemical Reactions January 9 th and 10 th

Chemical Reactions Bell ringer Below are two examples of chemical reactions. Answer the following questions about the below reactions. 1)Label the following parts: ReactantsProductsyields Coefficient subscript 2)Make a list of 3 things that the below reactions have in common. 3)Make a list of 3 things that are different about the below reactions. Mg + O 2 → 2 MgOZnS → Zn + S

The basic parts of a chemical reaction

Comparing reactions: Mg + O 2 → 2 MgOZnS → Zn + S

Types of Reactions 5 types of chemical reactions: 1.Synthesis reactions 2.Decomposition reactions 3.Single displacement reactions 4.Double displacement reactions A.Acid Base reactions B.Oxidation reduction reactions 5.Combustion reactions

Writing Reactions Identify the type of reaction. Predict the product(s) based on the type of reaction. Balance it: Law of conservation of matter: matter cannot be created or destroyed only transferred. Don’t forget about the diatomic elements! (gens) Oxygen is O 2 as an element. In a compound, it can’t be a diatomic element because it’s not an element anymore, it’s a compound!

Balancing Reactions All reactions must have same # of elements on each side of reaction… See data table provided.

Synthesis and Decomposition Monday January 14 th and 15 th

Synthesis reactions- Combination two substances (generally elements) combine and form a compound. reactant + reactant  1 product A + B  AB Example: 2H 2 + O 2  2H 2 O Example: C + O 2  CO 2

Synthesis Reactions Here is another example of a synthesis reaction

Practice Predict the products. Na (s) + Cl 2(g)  Mg (s) + F 2(g)  Al (s) + F 2(g) 

Decomposition Reactions Compound breaks up into the elements or in a few to simpler compounds Reactant  Product + Product AB  A + B Example: 2 H 2 O  2H 2 + O 2 Example: 2 HgO  2Hg + O 2

Types: Decomposition Example 2HgO → 2Hg + O 2  O Hg O OO + General: AB  A + B

Practice Predict the products. Then, write and balance the following decomposition reaction equations: Solid Lead (IV) oxide decomposes PbO 2(s)  Aluminum nitride decomposes AlN (s) 

Homework: Decomposition Pre-lab When finished get pre-lab checked and approved.

Replacement Reactions Wednesday January 16 th and Thursday January 17 th

Single Replacement Reactions one element replaces another in a compound. A metal replaces a metal (+) OR a nonmetal replaces a nonmetal (-). element + compound  compound + element 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!) When H 2 O splits into ions, it splits into H + and OH - (not H+ and O -2 !!)

Single Replacement Reaction Example Zinc metal reacts with aqueous hydrochloric acid Zn (s) + HCl (aq)  ZnCl 2 + H 2(g) Note: Zinc replaces the hydrogen ion in the reaction 2

Single displacement Example CuCl 2 + Zn → ZnCl 2 + Cu  Zn Cl Cu + AB + C  CB + A Cl Zn Cu +

Single Replacement Reactions Sodium chloride solid reacts with fluorine gas NaCl (s) + F 2(g)  NaF (s) + Cl 2(g) Note that fluorine replaces chlorine in the compound Aluminum metal reacts with aqueous copper (II) nitrate Solve the products for the below reaction: Al (s) + Cu(NO 3 ) 2(aq)  22

Double Replacement Reactions Metal replaces a metal in a compound and a nonmetal replaces a nonmetal in a compound. (Must be in solution) Compound + compound  compound + compound AB + CD  AD + CB

Double displacement Example MgO + CaS→ MgS + CaO General:AB + CD  AD + CB S O  Mg Ca + O S Mg Ca +

Double Replacement Reactions More examples: AgNO 3(aq) + NaCl (s)  AgCl (s) + NaNO 3(aq) K 2 SO 4(aq) + Ba(NO 3 ) 2(aq)  KNO 3(aq) + BaSO 4(s) 2

Practice Predict the products. Balance the equation 1.CaCl 2(aq) + Na 3 PO 4(aq)  2. Pb(NO 3 ) 2(aq) + BaCl 2(aq)  3. FeCl 3(aq) + NaOH (aq)  4. KOH (aq) + CuSO 4(aq) 

Homework Replacement Pre-lab When finished get approved

Replacement Reactions Lab Tuesday January 22 nd and Wednesday January 23 rd

Lab Safety Follow only directions give in your lab book. Safety goggles must be worn at all times. Area must be completely cleaned up when finished…. Once finished, you will copy down the notes that you find on the overhead.

Combustion Reactions hydrocarbon reacts with oxygen gas. called burning!!! In order to burn something you need the 3 things in the “fire triangle”: 1) A Fuel (hydrocarbon) 2) Oxygen 3) Something to ignite the reaction (spark)

Combustion Reactions In general: C x H y + O 2  CO 2 + H 2 O Products in combustion are ALWAYS carbon dioxide and water. Combustion is used to heat homes and run automobiles (octane, as in gasoline, is C 8 H 18 )

Combustion Example C 5 H 12 + O 2  CO 2 + H 2 O Write the products and balance the following combustion reaction: C 10 H 22 + O 2  5 6 8

Homework Finish your chemical reactions worksheet. Find all the reactions that are combustion reactions and label them… Then, balance them like shown in class.

STOP This is the end of notes for types of chemical reactions…