Transcript Breathalyzer

The Breathalyser Reaction
C2H2OH
+
Ethanol
Cr2O72- →
CH3COOH
Orange
Acetic Acid
+
Cr3+
Green
If the orange colour decreases there is alcohol present. It is measured
with a spectrophotometer. The more it decreases, the higher the blood
alcohol content.
Legal Limit Class 5 Licence
Legal Limit New Driver
Substance Oxidized
Substance Reduced
Reducing Agent
Oxidizing Agent
0.08 mg/mL
0.00 mg/mL
The Breathalyser Reaction
Look at the oxidation numbers!
-0.5
C2H2OH
+
Ethanol
+6
0
Cr2O72- →
CH3COOH
Orange
Acetic Acid
+3
+
Cr3+
Green
If the orange colour decreases there is alcohol present. It is measured
with a spectrophotometer. The more it decreases, the higher the blood
alcohol content.
Legal Limit Class 5 Licence
Legal Limit New Driver
Substance Oxidized
Substance Reduced
Reducing Agent
Oxidizing Agent
0.08 mg/mL
0.00 mg/mL
The Breathalyser Reaction
Look at the oxidation numbers!
-0.5
C2H2OH
+
Ethanol
+6
0
Cr2O72- →
CH3COOH
Orange
Acetic Acid
+3
+
Cr3+
Green
If the orange colour decreases there is alcohol present. It is measured
with a spectrophotometer. The more it decreases, the higher the blood
alcohol content.
Legal Limit Class 5 Licence
Legal Limit New Driver
Substance Oxidized
Substance Reduced
Reducing Agent
Oxidizing Agent
0.08 mg/mL
0.00 mg/mL
C2H2OH
The Breathalyser Reaction
Look at the oxidation numbers!
-0.5
C2H2OH
+
Ethanol
+6
0
Cr2O72- →
CH3COOH
Orange
Acetic Acid
+3
+
Cr3+
Green
If the orange colour decreases there is alcohol present. It is measured
with a spectrophotometer. The more it decreases, the higher the blood
alcohol content.
Legal Limit Class 5 Licence
Legal Limit New Driver
Substance Oxidized
Substance Reduced
Reducing Agent
Oxidizing Agent
0.08 mg/mL
0.00 mg/mL
C2H2OH
C2H2OH
The Breathalyser Reaction
Look at the oxidation numbers!
-0.5
C2H2OH
+
Ethanol
+6
0
Cr2O72- →
CH3COOH
Orange
Acetic Acid
+3
+
Cr3+
Green
If the orange colour decreases there is alcohol present. It is measured
with a spectrophotometer. The more it decreases, the higher the blood
alcohol content.
Legal Limit Class 5 Licence
Legal Limit New Driver
Substance Oxidized
Substance Reduced
Reducing Agent
Oxidizing Agent
0.08 mg/mL
0.00 mg/mL
C2H2OH
Cr2O72C2H2OH
The Breathalyser Reaction
Look at the oxidation numbers!
-0.5
C2H2OH
+
Ethanol
+6
0
Cr2O72- →
CH3COOH
Orange
Acetic Acid
+3
+
Cr3+
Green
If the orange colour decreases there is alcohol present. It is measured
with a spectrophotometer. The more it decreases, the higher the blood
alcohol content.
Legal Limit Class 5 Licence
Legal Limit New Driver
Substance Oxidized
Substance Reduced
Reducing Agent
Oxidizing Agent
0.08 mg/mL
0.00 mg/mL
C2H2OH
Cr2O72C2H2OH
Cr2O72-
Balance in acid solution
C2H2OH
+
Cr2O72- →
CH3COOH
+
Cr3+
Balance in acid solution
C2H2OH
+
Cr2O72- →
Cr2O72- →
C2H2OH
→
CH3COOH
Cr3+
CH3COOH
+
Cr3+
Balance in acid solution
C2H2OH
+
Cr2O72- →
Cr2O72- →
C2H2OH
→
CH3COOH
2Cr3+
CH3COOH
+
Cr3+
Balance in acid solution
C2H2OH
+
Cr2O72- →
CH3COOH
Cr2O72- →
2Cr3+ + 7H2O
C2H2OH +
H2O →
CH3COOH
+
Cr3+
Balance in acid solution
C2H2OH
+
Cr2O72- →
14H+ + Cr2O72- +
C2H2OH +
CH3COOH
→ 2Cr3+
H2O →
+
+ 7H2O
CH3COOH
+ H+
Cr3+
Balance in acid solution
C2H2OH
+
Cr2O72- →
14H+ + Cr2O72- + 6e- →
C2H2OH +
H2O →
CH3COOH
+
Cr3+
2Cr3+ + 7H2O
CH3COOH
+ H+ + 1e-
Balance in acid solution
C2H2OH
+
Cr2O72- →
CH3COOH
+
14H+ + Cr2O72- + 6e- →
2Cr3+ + 7H2O
6(C2H2OH +
→
H2O
Cr3+
CH3COOH+ H+ + 1e-)
Balance in acid solution
C2H2OH
+
Cr2O72- →
CH3COOH
+
14H+ + Cr2O72- + 6e- →
2Cr3+ + 7H2O
6(C2H2OH +
→
H2O
Cr3+
CH3COOH+ H+ + 1e-)
14H+ + Cr2O72- + 6C2H2OH + 6H2O → 2Cr3++7H2O+6CH3COOH+6H+
Balance in acid solution
C2H2OH
+
Cr2O72- →
CH3COOH
+
14H+ + Cr2O72- + 6e- →
2Cr3+ + 7H2O
6(C2H2OH +
→
H2O
Cr3+
CH3COOH+ H+ + 1e-)
8
1
14H+ + Cr2O72- + 6C2H2OH + 6H2O → 2Cr3++7H2O+6CH3COOH+6H+
Balance in acid solution
C2H2OH
+
Cr2O72- →
CH3COOH
+
14H+ + Cr2O72- + 6e- →
2Cr3+ + 7H2O
6(C2H2OH +
→
H2O
Cr3+
CH3COOH+ H+ + 1e-)
8H+ + Cr2O72- + 6C2H2OH → 2Cr3+ + 1H2O + 6CH3COOH
Balance in acid solution
C2H2OH
+
Cr2O72- →
CH3COOH
+
14H+ + Cr2O72- + 6e- →
2Cr3+ + 7H2O
6(C2H2OH +
→
H2O
Cr3+
CH3COOH+ H+ + 1e-)
8H+ + Cr2O72- + 6C2H2OH → 2Cr3+ + 1H2O + 6CH3COOH
+6
+6
Balance in base solution
8H+ + Cr2O72- + 6C2H2OH → 2Cr3+ + 1H2O + 6CH3COOH
Balance in base solution
8H+ + Cr2O72- + 6C2H2OH → 2Cr3+ + 1H2O + 6CH3COOH
8OH-
8OH-
Balance in base solution
8H+ + Cr2O72- + 6C2H2OH → 2Cr3+ + 1H2O + 6CH3COOH
8OH-
8H2O
8OH-
Balance in base solution
8H+ + Cr2O72- + 6C2H2OH → 2Cr3+ + 1H2O + 6CH3COOH
8OH-
8H2O
8OH-
Balance in base solution
Cr2O72- + 6C2H2OH → 2Cr3 + 1H2O + 6CH3COOH + 8OH7
8H2O
Balance in base solution
7H2O + Cr2O72- + 6C2H2OH → 2Cr3+ + 6CH3COOH + 8OH-
Review of Cells
Electrochemical
Electrolytic
Is a power supply
Spontaneous (+ ve)
Makes electricity
Requires power supply
Nonspontaneous(-ve)
Makes chemicals
Reduction is highest on Chart
Reduction is the –ve
For all cells:
Cations migrate to the cathode, which is the site of reduction.
Anions migrate to the anode, which is the site of oxidation.
Electrons travel through the wire from anode to cathode.
Complete the Chart
Electrochemical Cell: Zn, Zn(NO3)2 II Cu, CuSO4
Anode:
Reaction:
Cathode:
Reaction:
E0
=
Complete the Chart
Electrochemical Cell: Zn, Zn(NO3)2 II Cu, CuSO4
Anode:
Zn
Reaction:
Cathode:
Cu
Reaction:
E0
=
Higher on reduction Chart
Complete the Chart
Electrochemical Cell: Zn, Zn(NO3)2 II Cu, CuSO4
Anode:
Zn
Reaction: Zn → Zn2+ + 2e-
Cathode:
Cu
Reaction:
E0
0.76 v
=
Higher on reduction Chart
Complete the Chart
Electrochemical Cell: Zn, Zn(NO3)2 II Cu, CuSO4
Anode:
Zn
Reaction: Zn(s) → Zn2+ + 2e-
0.76 v
Cathode:
Cu
Reaction: Cu2+ + 2e- → Cu(s)
0.34 v
E0
=
Higher on reduction Chart
Complete the Chart
Electrochemical Cell: Zn, Zn(NO3)2 II Cu, CuSO4
Anode:
Zn
Reaction: Zn → Zn2+ + 2e-
0.76 v
Cathode:
Cu
Reaction: Cu2+ + 2e- → Cu(s)
0.34 v
E0
1.10 v
=
Higher on reduction Chart
Electrolytic Cell: Molten AlCl3
Anode:
Reaction:
Cathode:
Reaction:
Electrolytic Cell: Molten AlCl3
Anode:
C
Reaction:
Cathode:
C
Reaction:
Al3+
Cl-
Electrolytic Cell: Molten AlCl3
Anode:
C
Reaction:
Cathode:
C
Reaction:
Put the vowels together:
Anode
Anion
Oxidation
Al3+
Cl-
Oxidation of Anion
Electrolytic Cell: Molten AlCl3
Anode:
C
Reaction:
Cathode:
C
Reaction:
Put the vowels together:
Anode
Anion
Oxidation
Al3+
Cl-
2Cl- → Cl2 + 2e-
-1.36 v
Electrolytic Cell: Molten AlCl3
Anode:
C
Reaction:
Cathode:
C
Reaction:
Put the consonants together:
Cathode
Cation
Reduction
2Cl- → Cl2 + 2e-
-1.36 v
Electrolytic Cell: Molten AlCl3
Anode:
C
Reaction:
2Cl- → Cl2 + 2e-
-1.36 v
Cathode:
C
Reaction:
Al3+ + 3e- → Al
-1.66 v
Put the consonants together:
Cathode
Cation
Reduction
Reduction of Cation
Electrolytic Cell: Molten AlCl3
Anode:
C
Reaction:
2Cl- → Cl2 + 2e-
-1.36 v
Cathode:
C
Reaction:
Al3+ + 3e- → Al
-1.66 v
E0
=
-3.02 v
Electrolytic Cell: Molten AlCl3
Anode:
C
Reaction:
2Cl- → Cl2 + 2e-
-1.36 v
Cathode:
C
Reaction:
Al3+ + 3e- → Al
-1.66 v
E0
=
-3.02 v
MTV =
+3.02 v
Electrolytic Cell: KBr(aq)
Anode:
Cathode:
Electrolytic Cell: KBr(aq)
Anode:
C
Cathode:
C
K+
Br-
H2O
Electrolytic Cell: KBr(aq)
Anode:
C
Cathode:
C
Put the vowels together:
Anode
Anion or water
Oxidation
K+
Br-
H2O
Electrolytic Cell: KBr(aq)
Anode:
C
Cathode:
C
Oxidation of Anion or Water
Take Lower one!
2Br- → Br2 + 2e-
-1.09 v
Electrolytic Cell: KBr(aq)
Anode:
C
Cathode:
C
Oxidation of Anion or Water
Take Lower one!
2Br- → Br2 + 2e-
Put the consonants together:
Cathode
Cation or water
Reduction
-1.09 v
Electrolytic Cell: KBr(aq)
Oxidation of Anion or Water
Take Lower one!
Anode:
C
2Br- → Br2 + 2e-
-1.09 v
Cathode:
C
2H2O + 2e- → H2 + 2OH-
-0.41 v
Reduction of Cation or Water
Take Higher one!
Put the consonants together:
Cathode
Cation or water
Reduction
Electrolytic Cell: KBr(aq)
Oxidation of Anion or Water
Take Lower one!
Anode:
C
2Br- → Br2 + 2e-
-1.09 v
Cathode:
C
2H2O + 2e- → H2 + 2OH-
-0.41 v
E0
-1.50 v
=
Reduction of Cation or Water
Take Higher one!
Electrolytic Cell: KBr(aq)
Oxidation of Anion or Water
Take Lower one!
Anode:
C
2Br- → Br2 + 2e-
-1.09 v
Cathode:
C
2H2O + 2e- → H2 + 2OH-
-0.41 v
E0
-1.50 v
=
MTV =
+1.50 v
Reduction of Cation or Water
Take Higher one!
Electrochemical Cell: Ag, AgNO3 II Sn, Sn(NO3)2
Cathode:
Anode:
Electrochemical Cell: Ag, AgNO3 II Sn, Sn(NO3)2
Cathode:
Anode:
*higher
Ag
Electrochemical Cell: Ag, AgNO3 II Sn, Sn(NO3)2
Cathode:
Anode:
*higher
Ag
Ag+ + e- → Ag(s)
+0.80 v
Electrochemical Cell: Ag, AgNO3 II Sn, Sn(NO3)2
Cathode:
*higher
Ag
Anode:
Sn
Ag+ + e- → Ag(s)
+0.80 v
Electrochemical Cell: Ag, AgNO3 II Sn, Sn(NO3)2
Cathode:
*higher
Ag
Ag+ + e- → Ag(s)
+0.80 v
Anode:
Sn
Sn → Sn2+ + 2e-
+0.14 v
Electrochemical Cell: Ag, AgNO3 II Sn, Sn(NO3)2
Cathode:
*higher
Ag
2(Ag+ + e- → Ag(s))
+0.80 v
Anode:
Sn
Sn → Sn2+ + 2e-
+0.14 v
2Ag+ + Sn → Sn2+ + 2Ag(s)
E0
=
0.94 v