CH3COOH is the main constituent of vinegar. Zinc oxide is amphoteric, so I'm assuming that zinc is more electronegative than copper and accepts electrons during the reaction. CH3COOH being acidic must be an oxidising agent. Therefore when the current is on, CH3COOH breaks down into two ions, CH3CO+ and OH-, and copper is oxidised, hence explaining the bubbles on copper. Am I right? I can't explain the bubbles on zinc before the current is turned on...

Actually, when a metal reacts with an acid, a salt and hydrogen gas is produced.So when Zinc [ being a metal] reacts with ethanoic acid [ main constituent of vinegar], a salt Zinc ethanoate is produced along with hydrogen gas. We see the bubbles only because of the formation of hydrogen gas.

This blew my mind. What _did_ happen?

Here's what I think happened: upon adding the Zinc to the vinegar (or acetic acid CH3COOH) it reacts to form hydrogen gas (the bubbles) in the reaction Zn(s) + 2CH3COOH(aq) = Zn(CH3COO)2(aq) +H2(g); during this reaction the Zinc is Oxidised (it looses electrons) and becomes positively charged: *Zn = Zn^2+ + 2e-*. This is where I'm having trouble; I think the copper doesn't produce bubbles as it needs an oxidising agent present or the reaction is very slow because copper has what's known as a positive _reduction potential_ which just means that it is more likely to be reduced (gain electrons) than oxidised (lose electrons). When the wires are connected the electrons released from the Zinc produce a current and move to the copper; this gives the H+ ions in the acidic solution a chance to combine and form H2(g) which is released as bubbles.

what job does vinegar do there??

Vinegar is an acid. When acids touch metal, typically hydrogen gas is released. This hydrogen gas is our bubble. The vinegar also serves as an electrolyte by aiding electron migration or electric flow.

Main content

Zinc copper cell (reduction-oxidation)

Name: Zinc copper cell (reduction-oxidation)
Uploaded: 2013-02-19T07:01:13Z
Description: Zinc Copper cell - example of reduction-oxidation reaction

Google Classroom

Zinc Copper cell - example of reduction-oxidation reaction. Created by Brit Cruise.

Want to join the conversation?

Sort by:

eightsquare
Posted 11 years ago. Direct link to eightsquare's post “CH3COOH is the main const...”
CH3COOH is the main constituent of vinegar. Zinc oxide is amphoteric, so I'm assuming that zinc is more electronegative than copper and accepts electrons during the reaction. CH3COOH being acidic must be an oxidising agent. Therefore when the current is on, CH3COOH breaks down into two ions, CH3CO+ and OH-, and copper is oxidised, hence explaining the bubbles on copper. Am I right? I can't explain the bubbles on zinc before the current is turned on...
Button navigates to signup pageComment on eightsquare's post “CH3COOH is the main const...”
(10 votes)
Answer
- hrisikesh27
  Posted 11 years ago. Direct link to hrisikesh27's post “Actually, when a metal re...”
  Actually, when a metal reacts with an acid, a salt and hydrogen gas is produced.So when Zinc [ being a metal] reacts with ethanoic acid [ main constituent of vinegar], a salt Zinc ethanoate is produced along with hydrogen gas. We see the bubbles only because of the formation of hydrogen gas.
  Button navigates to signup page
  (12 votes)
Dane Sheridan
Posted 11 years ago. Direct link to Dane Sheridan's post “This blew my mind. What _...”
This blew my mind. What did happen?
Button navigates to signup pageButton navigates to signup page
(4 votes)
Answer
- Simeon Nichols
  Posted 11 years ago. Direct link to Simeon Nichols's post “Here's what I think happe...”
  Here's what I think happened: upon adding the Zinc to the vinegar (or acetic acid CH3COOH) it reacts to form hydrogen gas (the bubbles) in the reaction Zn(s) + 2CH3COOH(aq) = Zn(CH3COO)2(aq) +H2(g); during this reaction the Zinc is Oxidised (it looses electrons) and becomes positively charged: *Zn = Zn^2+ + 2e-*. This is where I'm having trouble; I think the copper doesn't produce bubbles as it needs an oxidising agent present or the reaction is very slow because copper has what's known as a positive reduction potential which just means that it is more likely to be reduced (gain electrons) than oxidised (lose electrons). When the wires are connected the electrons released from the Zinc produce a current and move to the copper; this gives the H+ ions in the acidic solution a chance to combine and form H2(g) which is released as bubbles.
  Comment on Simeon Nichols's post “Here's what I think happe...”
  (3 votes)
yasser
Posted 10 years ago. Direct link to yasser's post “what job does vinegar do ...”
what job does vinegar do there??
Button navigates to signup pageButton navigates to signup page
(3 votes)
Answer
- Exponentially Radical
  Posted 10 years ago. Direct link to Exponentially Radical's post “Vinegar is an acid. When ...”
  Vinegar is an acid. When acids touch metal, typically hydrogen gas is released. This hydrogen gas is our bubble. The vinegar also serves as an electrolyte by aiding electron migration or electric flow.
  Button navigates to signup page
  (2 votes)
Function 97
Posted 11 years ago. Direct link to Function 97's post “Why was he using vinegar?...”
Why was he using vinegar? Would water work?
Button navigates to signup pageComment on Function 97's post “Why was he using vinegar?...”
(3 votes)
Answer
- Neil Balch
  Posted 11 years ago. Direct link to Neil Balch's post “Probably not, Vinegar has...”
  Probably not, Vinegar has special acidic properties that make it better than water for this purpose.
  Button navigates to signup page
  (1 vote)
Jack Owen
Posted 10 years ago. Direct link to Jack Owen's post “How come when the two wir...”
How come when the two wires connect the copper does not erode?
Button navigates to signup pageButton navigates to signup page
(3 votes)
Answer
- brit cruise
  Posted 10 years ago. Direct link to brit cruise's post “Great question. Perhaps I...”
  Great question. Perhaps I should observe the reaction over the course of 24 hours and post the new evidence.
  Comment on brit cruise's post “Great question. Perhaps I...”
  (1 vote)
UMARBFD786
Posted 9 years ago. Direct link to UMARBFD786's post “wouldn't he get an electr...”
wouldn't he get an electric shock
Button navigates to signup pageButton navigates to signup page
(1 vote)
Answer
CielAllen08
Posted 9 years ago. Direct link to CielAllen08's post “where can you get those w...”
where can you get those wires that he has if you want to do the experiment yourself?
Button navigates to signup pageComment on CielAllen08's post “where can you get those w...”
(1 vote)
Answer
Carmel01
Posted 9 years ago. Direct link to Carmel01's post “If you put a light bulb o...”
If you put a light bulb on the end with the copper wire instead of the wire would the light bulb light up?
Button navigates to signup pageButton navigates to signup page
(1 vote)
Answer
Abigail Abigail
Posted 9 years ago. Direct link to Abigail Abigail's post “What is zinc?”
What is zinc?
Button navigates to signup pageButton navigates to signup page
(2 votes)
Answer
Abigail Abigail
Posted 9 years ago. Direct link to Abigail Abigail's post “What is zinc?!”
What is zinc?!
Button navigates to signup pageButton navigates to signup page
(2 votes)
Answer
- Martin Campo
  Posted 9 years ago. Direct link to Martin Campo's post “Zinc is a metallic elemen...”
  Zinc is a metallic element with the symbol Zn and atomic number 30. It is the first element in group 12.
  Button navigates to signup page
  (1 vote)