Quiz #4 Chemical Rxns and Safety 1.Why is it important to avoid eating in a chemistry lab? 2.What is the correct way to write the formula for Chlorine? 3.In the formula (NH 4 ) 2 SO 4 What elements are present? 4.How many of each element is present in the formula of ammonium sulfate (in question 3)? 5.Balance the following: __H 2 + __N 2  __NH 3 6.What does C 3 H 8 (l) symbolize if this is the symbol for propane? 7.Predict the following reaction: __K + __Cl 2  ______ 1.Poisonous chemicals could be left on the desk from previous experiments, eating in lab makes it likely that you will poison yourself. 2.Cl 2 3.N, S, H, and O 4.2 N, 1 S, (2 x 4 =) 8 H, 4 O 5. 3 H 2 + N 2  2 NH 3 6.Liquid propane 7.2 K + Cl 2  2 KCl

Practice Synthesis Rxns Active metal oxides react with water to form hydroxides. ex: Na 2 O + H 2 O  ________ Many oxides of nonmetals react with water to form oxyacids. ex: P 2 O H 2 O  _2________ Some metal oxides react with nonmetal oxides to form salts. K 2 O + SO 3  ________ Active metals react with halogens to form salts. __Na + Br 2-  2NaOH H 3 PO 4 K 2 SO 4 2 NaBr2

Practice Decomposition reactions __NaOH  __Cr(OH) 3  __MgCO 3  __KClO 3  __Ca(ClO 3 ) 2  __Ca(OH) 2  2 NaOH  Na 2 O + H 2 O 2 Cr(OH) 3  Cr 2 O 3 + 3H 2 O MgCO 3  MgO + 3 CO 2 2 KClO 3 -> 2KCl + 3 O 2 Ca(ClO 3 ) 2  CaCl O 2 Ca(OH) 2  CaO + H 2 O

Single Displacement A+ BX  AX + B or: Y + BX  BY + X Replacement of a metal in a compound by another metal. 2 Al (s) + 3Pb(NO 3 ) 2  3Pb +2 Al(NO 3 ) 3 Al Pb 2+ N O O O N O O O N O O O N O O O N O O O N O O O

Single Displacement A+ BX  AX + B or: Y + BX  BY + X Replacement of a metal in a compound by another metal. 2 Al (s) + 3Pb(NO 3 ) 2  3Pb +2 Al(NO 3 ) 3 Al 3+ Pb N O O O N O O O N O O O N O O O N O O O N O O O

Single Displacement A+ BX  AX + B or: Y + BX  BY + X Replacement of a hydrogen in a compound by a metal. 2 Na (s) + 2 H 2 O (l)  2 NaOH (aq) + H 2 (g) Na O H H O H H

Single Displacement A+ BX  AX + B or: Y + BX  BY + X Replacement of a hydrogen in a compound by a metal. Mg (s) + 2 HCl (aq)  MgCl 2 (aq) + H 2 (g) Mg Cl H H

Single Displacement A+ BX  AX + B or: Y + BX  BY + X Replacement of halogens Cl 2 (g) + 2 KBr (aq)  2 KCl (aq) + Br 2 (g) Cl K Br K Cl

Practice: Single Replacement Mg + 2 HCl  2 Fe + 6 HCl  Zn + CuCl 2  Cu + ZnCl 2  Ni + PbCl 2  Sn + PbCl 2  Fe + 3 AgNO 3  H 2 + MgCl 2 3 H FeCl 3 Cu + ZnCl 2 No reaction Pb + NiCl 2 SnCl 2 + Pb Fe(NO 3 ) 3 + 3Ag LithiumFluorine PotassiumChlorine BariumBromine StrontiumIodine Calcium Sodium Magnesium Aluminum Manganese Zinc Iron Cadmium Cobalt Nickel Tin Lead Hydrogen Copper Silver Mercury Gold Elements CANNOT replace anything Above them. The reaction does NOT occur in this situation Less active 

Double Replacement Reactions (double displacement) Formation of a precipitate. 2 KI (aq) + Pb(NO 3 ) 2 (aq)  PbI 2 (s) + 2 KNO 3 (aq) K K I Pb 2+ N O O O N O O O I

Double Replacement Reactions (double displacement) Formation of a gas. FeS (s) + 2 HCl(aq)  H 2 S (g) + FeCl 2 (aq) Fe 2+ S Cl H H

Double Replacement Reactions (double displacement) Formation of a water. NaOH (s) + HCl(aq)  H 2 O (l) + NaCl 2 (aq) Na + Cl H O H

Combustion Reactions A substance combines with oxygen, releasing a large amount of energy in the form of light and heat. 2 H 2 (g) + O 2 (g)  2 H 2 O O H H O H H

Combustion Reactions A substance combines with oxygen, releasing a large amount of energy in the form of light and heat. C 3 H 8 (g) +5 O 2 (g)  4 H 2 O + 3 CO 2 C CC H H H H H H H H O O O O O O O O O O

Combustion Reactions A substance combines with oxygen, releasing a large amount of energy in the form of light and heat. C 3 H 8 (g) +5 O 2 (g)  4 H 2 O + 3 CO 2 C C C H H H H H H H H O O O O O O O O O O