6K.1

[Letty Liu 2C]

The following redox reaction is used in acidic solution in
the Breathalyzer test to determine the level of alcohol in blood: H1 (aq) 1 Cr2O722 (aq) 1 C2H5OH(aq) ¡
Cr31 (aq) 1 C2H4O(aq) 1 H2O(l)
Identify the elements undergoing oxidation or reduction and indicate their initial and final oxidation numbers. (b) Write and balance the oxidation half-reaction. (c) Write and balance the reduction half-reaction. (d) Combine the half-reactions to produce a balanced redox equation.

How do I approach this problem? I don't understand how to calculate the charge on C2H5OH.

[Megan Vu 1J]

To first approach the question, you should see at which indicate which part is being oxidized and reduced. To see a compound's overall charge, you should look at the superscript. To look at the charge of the compound as a whole, you should be able to see the total net charge. Then, look at the individual components of each chemical equation to determine the oxidation charge. Thus, you should be able to calculate the charges and therefore, find the rest of the parts.