Question

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I want to find the half equations in the redox reaction between chlorine gas and water?

Cl_2(g) + H₂O_(l) -> HOCl_(aq) + HCl_(aq)

asked Feb 17 at 0:05

Hugh
797●8

	Is there any way to subscript numbers and states? – Hugh Feb 17 at 0:05
	Yep, use <sup>superscript text</sup> and <sub>subscript text</sub> HTML tags :) – Collin Li♦ Feb 17 at 7:45
	Thanks Colin... – Hugh Feb 17 at 9:53

Lam Nguyen · Accepted Answer · 2010-02-17 04:39:26Z UTC

Assign the oxidation states to the elements.

Elemental substances assume ox state of 0, such as Al, Cl2, etc.

Neutral compounds have overall ox state of 0, like H2O: ox(H) = +1, ox(O) = -2, have 2 Hs and 1 O so overall oxidation state is 2x(+1) + (-2) = 0.

O (oxygen) in compounds usually has ox state of -2 (with some exceptions like H2O2 but not frequently encountered).

H in compound usually is +1.

In this case:

Cl in Cl2 = 0

Cl in HOCl = +1 (because H = +1, O = -2 so Cl = +1 to make the whole HOCl have ex state of 0)

Cl in HCl = -1

Oxidation:Cl2 -> HOCl

Reduction: Cl2 -> HCl

Then balance the two half equations.

Note: The book should have a dedicated chapter for this.

How to find the half equations in the redox reaction between chlorine gas and water?

1 Answer