Can someone check my equations for battery cells im unsure if theyre combined correct (1 Viewer)

Kaatie · Nov 1, 2008

Leclanché

<TABLE class=MsoTableGrid style="BORDER-RIGHT: medium none; BORDER-TOP: medium none; BORDER-LEFT: medium none; BORDER-BOTTOM: medium none; BORDER-COLLAPSE: collapse; mso-border-alt: solid windowtext .5pt; mso-yfti-tbllook: 480; mso-padding-alt: 0cm 5.4pt 0cm 5.4pt; mso-border-insideh: .5pt solid windowtext; mso-border-insidev: .5pt solid windowtext" cellSpacing=0 cellPadding=0 border=1><TBODY><TR style="mso-yfti-irow: 0"><TD style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: windowtext 1pt solid; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 1pt solid; WIDTH: 131.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt" vAlign=top width=219>Anode
(oxidation)<O

</TD><TD style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: windowtext 1pt solid; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 311.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" vAlign=top width=519>Zinc (container)<O
Zn(s) -> Zn2+(aq) +2e- <O

</O

</TD></TR><TR style="mso-yfti-irow: 1"><TD style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 1pt solid; WIDTH: 131.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign=top width=219>Cathode<O

(reduction)<O

</TD><TD style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 311.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign=top width=519>C/MnO2<O</O
NH4(s)+ + MnO2(s) + H2O(l)+ + e- ->Mn(OH)3(s)+ NH3(aq)<O

</O

Manganese is reduced from an oxidation state of +4 to +3

</TD></TR><TR style="mso-yfti-irow: 2; mso-yfti-lastrow: yes"><TD style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 1pt solid; WIDTH: 131.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign=top width=219>Overall chemical equation<O

</O

</TD><TD style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 311.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign=top width=519>Zn(s) + N(s) + 4H+(aq) + MnO2(s) + H2O(l) -> Zn2+(aq) + Mn2O3(s) + NH3(aq)<O

</O

</TD></TR></TBODY></TABLE>

Lithium- iodine
<TABLE class=MsoTableGrid style="BORDER-RIGHT: medium none; BORDER-TOP: medium none; BORDER-LEFT: medium none; BORDER-BOTTOM: medium none; BORDER-COLLAPSE: collapse; mso-border-alt: solid windowtext .5pt; mso-yfti-tbllook: 480; mso-padding-alt: 0cm 5.4pt 0cm 5.4pt; mso-border-insideh: .5pt solid windowtext; mso-border-insidev: .5pt solid windowtext" cellSpacing=0 cellPadding=0 border=1><TBODY><TR style="mso-yfti-irow: 0"><TD style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: windowtext 1pt solid; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 1pt solid; WIDTH: 311.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt" vAlign=top width=519>Lithium<O
Li[FONT=Times New (W1)](s) ->[/FONT] Li+[FONT=Times New (W1)](s) + e-<O

[/FONT]

</TD></TR><TR style="mso-yfti-irow: 1"><TD style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 1pt solid; WIDTH: 311.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign=top width=519>Steel/I2 polymer<O
I[FONT=Times New (W1)]2(s) + 2e[FONT=Times New (W1)]-[/FONT] goes to[/FONT] 2I[FONT=Times New (W1)]-[FONT=Times New (W1)](s)[/FONT][FONT=Times New (W1)]<O

[/FONT][/FONT]
[FONT=Times New (W1)]The cathode is composed of an iodine-poly-2-vinylpridine charge transfer complex. <O

[/FONT]

</TD></TR><TR style="mso-yfti-irow: 2; mso-yfti-lastrow: yes"><TD style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 1pt solid; WIDTH: 311.4pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign=top width=519>Li[FONT=Times New (W1)](s) + I2[FONT=Times New (W1)](s)[/FONT] [/FONT]-> Li+[FONT=Times New (W1)](s)[FONT=Times New (W1)] + [/FONT]2I[FONT=Times New (W1)]-[/FONT][FONT=Times New (W1)](s)[/FONT][/FONT][FONT=Times New (W1)]<O

[/FONT]

</TD></TR></TBODY></TABLE>

Note: only used the words goes to because aparently i had to many symbols to post it

SkimDawg · Nov 1, 2008

Both correct. If your planning on using one of those for the hsc, use the lithium one, the 'dry / leclanche cell' is incredibly hard to remember.

danz90 · Nov 1, 2008

SkimDawg said:
Both correct. If your planning on using one of those for the hsc, use the lithium one, the 'dry / leclanche cell' is incredibly hard to remember.

lol I agree, but the Leclanche one has just stuck in my head now. It is incredibly long.. but meh after one year of it it just gets stuck in ur head.

brenton1987 · Nov 4, 2008

The overall chemical reaction for the Leclanche cell should be

Zn_(s) + 2 MnO2_(s) + 2 NH4Cl_(aq) --> ZnCl2_(aq) + Mn2O3_(s) + 2 NH3_(aq) + H2O

The cathode reaction is wrong.

Azreil · Nov 4, 2008

Remember to double equations so that the e- balance out on both sides! :]

danz90 · Nov 4, 2008

brenton1987 said:
The overall chemical reaction for the Leclanche cell should be

Zn_(s) + 2 MnO2_(s) + 2 NH4Cl_(aq) --> ZnCl2_(aq) + Mn2O3_(s) + 2 NH3_(aq) + H2O

The cathode reaction is wrong.

Isn't Mn(OH)₃(s) produced, not Mn2O3

mcs-one · Nov 4, 2008

brenton1987 said:
The overall chemical reaction for the Leclanche cell should be

Zn_(s) + 2 MnO2_(s) + 2 NH4Cl_(aq) --> ZnCl2_(aq) + Mn2O3_(s) + 2 NH3_(aq) + H2O

The cathode reaction is wrong.

cant u just simplify it:

Mn4+ (aq) + e- -> Mn3+ (s)

brenton1987 · Nov 4, 2008

danz90 said:
Isn't Mn(OH)₃(s) produced, not Mn2O3

No Mn(OH)₃ is not a product that can be isolated.

1. Zn_(s) ---> Zn²⁺_(aq) + 2 e^-
2. 2 NH₄⁺_(aq) + 2 e^- ---> 2 NH_3(g) + H_2(g)
3. 2 MnO_2(s) + H_2(g) ---> Mn₂O_3(s) + H₂O_(l)

Total
Zn_(s) + 2 MnO_2(s) + 2 NH₄Cl_(aq) --> ZnCl_2(aq) + Mn₂O_3(s) + 2 NH_3(aq) + H₂O

Because Cl^- is only a spectator it can be removed.
Zn_(s) + 2 MnO_2(s) + 2 NH₄⁺_(aq) --> Zn²⁺_(aq) + Mn₂O_3(s) + 2 NH_3(aq) + H₂O

danz90 · Nov 4, 2008

brenton1987 said:
No Mn(OH)₃ is not a product that can be isolated.

1. Zn_(s) ---> Zn²⁺_(aq) + 2 e^-
2. 2 NH₄⁺_(aq) + 2 e^- ---> 2 NH_3(g) + H_2(g)
3. 2 MnO_2(s) + H_2(g) ---> Mn₂O_3(s) + H₂O_(l)

Total
Zn_(s) + 2 MnO_2(s) + 2 NH₄Cl_(aq) --> ZnCl_2(aq) + Mn₂O_3(s) + 2 NH_3(aq) + H₂O

Because Cl^- is only a spectator it can be removed.
Zn_(s) + 2 MnO_2(s) + 2 NH₄⁺_(aq) --> Zn²⁺_(aq) + Mn₂O_3(s) + 2 NH_3(aq) + H₂O

Well, wouldn't Manganese(III) Hydroxide be produced anyway, because MnO₂ is a basic oxide (Mn is a transition metal), and then when it reacts with the water, it would produce a base?

Kaatie · Nov 4, 2008

glad to see im not the only one confused lol

Kaatie · Nov 4, 2008

brenton1987 said:
No Mn(OH)₃ is not a product that can be isolated.

1. Zn_(s) ---> Zn²⁺_(aq) + 2 e^-
2. 2 NH₄⁺_(aq) + 2 e^- ---> 2 NH_3(g) + H_2(g)
3. 2 MnO_2(s) + H_2(g) ---> Mn₂O_3(s) + H₂O_(l)

Total
Zn_(s) + 2 MnO_2(s) + 2 NH₄Cl_(aq) --> ZnCl_2(aq) + Mn₂O_3(s) + 2 NH_3(aq) + H₂O

Because Cl^- is only a spectator it can be removed.
Zn_(s) + 2 MnO_2(s) + 2 NH₄⁺_(aq) --> Zn²⁺_(aq) + Mn₂O_3(s) + 2 NH_3(aq) + H₂O

thanks so much i had actually changed it to this after reading over the topic better but its great to get it confirmed

and yes i realised i forgot to double the other equation for lithium. oh and i didnt realise there were two cathode reactions thanks for that

.

btw, how did you go in your hsc? what subjects did you do?

answer now reads:
Zinc (container)
Zn(s) * Zn2+(aq) +2e-
C/MnO2
There are two reduction reactions
• 2 NH4+(aq) + 2 e- ---> 2 NH3(g) + H2(g)
• 2 MnO2(s) + H2(g) ---> Mn2O3(s) + H2O(l)

These combine to make an overall equation of
2MnO2(s) + 2NH4+(aq) + 2e- * Mn2O3(s)+ H2O(l) + 2NH3+
Net: 2MnO2(s) + 2H+(aq) + 2e- * Mn2O3(s)+ H2O(l)

Manganese is reduced from an oxidation state of +4 to +3.
Ionic:
Zn(s) + 2 MnO2(s) + 2 NH4Cl(aq) --> ZnCl2(aq) + Mn2O3(s) + 2 NH3(aq) + H2O
Net ionic:
Zn(s) + 2 MnO2(s) + 2 NH4+(aq) --> Zn2+(aq) + Mn2O3(s) + 2 NH3(aq) + H2O

and for lithium
Lithium
Li(s) * Li+(s) + e-
Steel/I2 polymer
I2(s) + 2e- * 2I-(s)
The cathode is composed of an iodine-poly-2-vinylpridine charge transfer complex.
2Li(s) + I2(s) * 2I-(s) + 2Li+(s)

Azreil · Nov 5, 2008

The notes I have state the equation you had previously and Danz is talking about for the dry cell.

kangms · Nov 5, 2008

Hope that they don't ask a battery question this year...I know jack crap about Batteries..

cherrii--X · Nov 13, 2008

omggggg

i am confused.

Can someone check my equations for battery cells im unsure if theyre combined correct (1 Viewer)

Kaatie

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