I have an electronics maintainer exam coming up and I was studying from a book that I had bought off of Amazon.
One of the question stated:
The normal cell voltage of a fully-charged nickel-cadmium battery is __________ volts.
A. 2.0
B. 1.5
C. 1.4
D. 1.0
The book said the correct answer was C. 1.4V but when I Google the voltage of a fully-charged nickel-cadmium battery multiple sources are saying that it's 1.2V.
Is the book wrong or could they both be correct like 1.2V-1.4V range for a fully-charged nickel-cadmium battery?
Any insight would be helpful.
I've been trying to understand this topic from the Kaplan GC book for about 2 weeks now and I still do not get it. Does anyone have a really basic way of understand what is going in these? I see the half reactions but I do not understand how they are happening. For ex for
2NiO(OH) + H2O + 2e- => 2Ni(OH)2 + 2OH-
How does this even work? Like the Nickel Oxide just gives up the OH-???
Studying gen chem electrochem rn and theres like 2 pages on this stuff I never heard about.
So I'm looking at buying an electric Peugeot 106 with nickel cadmium batteries. The car has only 40.000km which isn't much for a car from 2000, but I'm thinking, will the batteries be in good condition, and if they aren't, how much is a replacement? Thanks in advance!
Please correct me if i'm wrong: Since Ni-Cd batteries are rechargeable in the discharge state they act as a galvanic cell where the anode is the Cd (-) and the cathode is NiO(OH) (+), and the oxidation of Cd to form Cd(OH)2 and 2e- is supplying the 2e- that travel from the anode to the cathode to reduce the NiO(OH) to Ni(OH)2.
When charging, they would act as an electrolytic cell. This is where i believe I might be making an error. From my knowledge, in an electrolytic cell the + and - stay on the same bar as it was on in the galvanic, so the Cd(OH)2 will be (-), and Ni(OH)2 will be (+) still. But the cathode and anode designations switch, as the Cd(OH)2 will be reduced making it now the cathode, and the Ni(OH)2 will be oxidized making it now the anode. So the reverse rxn's will result in the 2e- traveling from the anode (+) Ni bar to the cathode (-) Cd bar.
I am reading a text (Kaplan MCAT Gen Chem Chap 12, concept check 12.1 table 6) where it state that in the charging state the anode material is actually Cd(OH)2 (+) and the cathode material is actually Ni(OH)2 (-). This goes against my understanding of how electrolytic cells/Ni-Cd batteries work.
Based on this text, is it that when charging a cell such as a NiCd or lead-acid battery, all that happens is that the +/- is switched but the cathode-anode designations stay the same? This would imply (and i could be wrong in my understanding of electrolytic cells as well) that when charging a NiCd or Lead-acid battery it is not the same as an electrolytic cell in terms of designations. Thanks for any light you can help shed on this!
UPDATE: I believe my interpretation of the kaplan table was incorrect. The table stated anode material/cathode material. In the discharging Ni-Cd battery the anode (-) is Cd, and the cathode (+) is NiO(OH). After discharge is complete the anode material is just the oxidized form of Cd(OH)2, and the cathode material is Ni(OH)2. When you charge this battery the signs flip but the material stays the same, so the anode material is Cd(OH)2 and you are trying to reduce it so that it can act as a functioning anode again hence anode material in charging state is Cd(OH)2 with a (+) designation. (in this charging cell the species being oxidized/the anode is the Ni(OH)2 but as we are talking about a rechargeable batter the anode material is still the Cd electrode).
So I bought this vacuum, the BLACK+DECKER CHV1510 Dustbuster Cordless Cyclonic Hand Vacuum a couple years ago and couldn't tell why it wasn't holding a charge after a couple months. Then I realized that it's a nickel cadmium battery. My recollection from playing with RC cars as a kid is that NiCd batteries do not keep their lives very long, especially if plugged in all the time, which I did whenever I wasn't using this vacuum.
So I took it apart and got the battery out. Now I just can't figure out what to replace it with. I'd love to not go with another NiCd battery... Any help? Here are some pictures of the battery.
SuperiorLighting.com carries an exit sign battery (SKU Nickel Cadmium Exit Battery 4.8v 700mA) that is a drop in replacement for the OEM battery. Just need to solder the wires to the board. Fits perfectly, is 100 mA higher capacity, and works. $6.38 not including shipping.
Did mine with no issues. See included pictures.
http://imgur.com/gallery/AJ7IIof
I was exploring some wasteland near where I live and found a really hidden area in some bushes that'd obviously been used for.. something. There was a lot of old police tape around the area.
There were about 400 nickel cadmium batteries, twenty or so bottles of bleach, a lot of plastic corrugated piping, torn up trousers and scraps on cloth (possibly an easy filter?), and some rusted metal buckets and drums with 'goo' in the bottom.
This was all in a ten foot deep hole in the ground, in the middle of a dense scrubland, there would be absolutely no way to get a digger in.
Can anyone think of what they were doing? Something like meth springs to mind, but I don't know the chemistry - I thought that was lithium, not cadmium.
This is the exact battery http://www.amazon.com/3M-GVP-111-Battery-Rechargeable-70070515575/dp/B0013HDUD8
It's a 4.8 V battery.
EDIT: Measuring voltage probably won't work. Unlike most batteries, NiCd batteries do not experience a voltage drop as they are depleted. http://www.batterystuff.com/kb/articles/battery-articles/what-the-heck-is-a-nicd-battery.html
They should add Lithium, Beryllium, Sodium, Magnesium, Aluminum, Potassium, Calcium, Scandium, Titanium, Vanadium, Chromium, Manganese, Cobalt, Nickel, Zinc, Gallium, Rubidium, Strontium, Yttrium, Zirconium, Niobium, Molybdenum, Technetium, Ruthenium, Rhodium, Palladium, Silver, Cadmium, Indium, Tin, Cesium, Barium, Lanthanum, Cerium, Praseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, Hafnium, Tantalum, Tungsten, Rhenium, Osmium, Iridium, Platinum, Mercury, Thallium, Lead, Bismuth, Polonium, Francium, Radium, Actinium, Thorium, Protactinium, Uranium, Neptunium, Plutonium, Americium, Curium, Berkelium, Californium, Einsteinium, Fermium, Mendelevium, Nobelium, Lawrencium, Rutherfordium, Dubnium, Seaborgium, Bohrium, Hassium, Meitnerium, Darmstadtium, Roentgenium, Copernicium, Nihonium, Flerovium, Moscovium, and Livermorium.
For realism.
I was shopping online when I found a bracelet I liked. When looking at the "Materials", it only mentioned that. What does that mean in terms of "safety/toxicity"?
Please correct me if i'm wrong: Since Ni-Cd batteries are rechargeable in the discharge state they act as a galvanic cell where the anode is the Cd (-) and the cathode is NiO(OH) (+), and the oxidation of Cd to form Cd(OH)2 and 2e- is supplying the 2e- that travel from the anode to the cathode to reduce the NiO(OH) to Ni(OH)2.
When charging, they would act as an electrolytic cell. This is where i believe I might be making an error. From my knowledge, in an electrolytic cell the + and - stay on the same bar as it was on in the galvanic, so the Cd(OH)2 will be (-), and Ni(OH)2 will be (+) still. But the cathode and anode designations switch, as the Cd(OH)2 will be reduced making it now the cathode, and the Ni(OH)2 will be oxidized making it now the anode. So the reverse rxn's will result in the 2e- traveling from the anode (+) Ni bar to the cathode (-) Cd bar.
I am reading a text (Kaplan MCAT Gen Chem Chap 12, concept check 12.1 table 6) where it state that in the charging state the anode material is actually Cd(OH)2 (+) and the cathode material is actually Ni(OH)2 (-). This goes against my understanding of how electrolytic cells/Ni-Cd batteries work.
Based on this text, is it that when charging a cell such as a NiCd or lead-acid battery, all that happens is that the +/- is switched but the cathode-anode designations stay the same? This would imply (and i could be wrong in my understanding of electrolytic cells as well) that when charging a NiCd or Lead-acid battery it is not the same as an electrolytic cell in terms of designations. Thanks for any light you can help shed on this!
