Reactions- L13

Question 1

The Activity Series

Answer 1

• elements that are less easily oxidized will oxidize elements that are more easily oxidized
• Elements can be listed, one on top of the other, in order of increasing or decreasing activity
• easier to oxidize/ will oxidize the further down the list

Question 2

single replacement- a copper (II) nitrate solution is poured over solid zinc

Answer 2

• Use activity series to see who bonds
• take out dissolved
• write out half reactions
• combine

Question 3

Halogen Displacement Redox Reactions

Answer 3

• Halogens that are bonded to themselves can take electrons from (oxidize) and halide ions that is below it in the family
• F2>Cl2>Br2>I2

Question 4

Halogen Displacement Redox Reactions- chlorine gas is bubbled through an aqueous solution containing potassium bromide

Answer 4

• single replacement- use activity series to see if it works
• half reactions
• multiply by electrons to cancel
• combine

Question 5

Hydrogen displacement redox reactions

Answer 5

• in these reactions, the hydrogen atoms in H2O are reduced as they gain electrons to form hydrogen gas
• Alkali metals, Ca, Sr, and Ba will displace hydrogen
• H20 + e- ==> H2 + OH-

Question 6

Hydrogen displacement redox reactions

Answer 6

• Half reaction for H2O (2H2O + 2e- ==> H2 + 2OH-
• Half reaction for element (Na==> 2Na+ + 2e-)
• Combine

Question 7

Disproportionation Reaction

Answer 7

• An element in one oxidation state simultaneously undergoes both oxidation and reduction
• The element must have 3 oxidation states, and it must be in an intermediate state

Question 8

Disproportionation Reaction (A solution of Copper (1) Chloride sits in a beaker for an extended period of time)

Answer 8

• Look at the activity series
• write the 2 half reaction things from the sheet
• Combine

Question 9

Disproportionation Reaction with intermediate state

Answer 9

• Like elements existing together in two oxidation states can undergo a redox reaction to produce a species in an intermediate oxidation state
• The element must, therefore, have at least three oxidation states, and therefore must be an intermediate state that falls between the states of reactants

Question 10

Disproportionation Reaction with intermediate state (solid iron fillings are added to a .5M solution of iron (III) chloride)

Answer 10

• write the two reactions from the sheet
• combine
• products will end up with the intermediate charge

Question 11

Combustion reactions- combustion of organic compounds

Answer 11

• The combustion of any organic hydrocarbon in the presence of oxygen gas produces CO2 and H2O
• organic=hydrocarbon
• ex. methane burned in air

Question 12

Combustion reactions- combustion of elements

Answer 12

• The combustion of any element in the presence of oxygen produces its oxide
• ex. sulfur is burned in air (S+O==>SO2)
• calcium is burned in air (Ca+O2==>2CaO)

Question 13

Other redox reactions

Answer 13

• when the oxidation numbers assigned to the elements in two compounds are at opposite extremes, a REDOX reaction may take place to produce more common oxidation states
• ex hot iron (II) oxide is added to a vessel containing carbon monoxide gas

Question 14

Acids

Answer 14

• Acids donate protons in aqueous solutions

- Strong acids like HCl and H2SO4 experience 100% dissociation in polar solvents, just like soluble ionic compounds

Question 15

Redox reactions in Acidic Solutions

Answer 15

• Reactions between metals and all strong acids Nitric Acid
• H+ ions can oxidize many metals (X)
• H+ (aq) + X(s) ==> H2(g) + X^a+ (aq)
• H stays and other stuff is dissolved

Question 16

High vs. low on list

Answer 16

• high oxidizes low

- low reduces high