Title: Name:
Author: P Lawson

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Chemistry 30
Unit 6: Redox Reactions and Electrochemistry
Assignment 1 Redox Reactions and Oxidation Numbers

1.	Define oxidation and reduction.

2.	Determine the oxidation number of nitrogen in each of the following compounds:

	a.	NH_3						c.	Ca_3N_2

	b.	NO_2						d.	NI_3		

3.	Determine the oxidation numbers of the underlined  element in the following compounds:

	a.	SO_2						e.	H_3BO_3	

	b.	MnO_2						f.	Na_2O_2 (sodium peroxide)	

	c.	Cr^3+							g.	Sn	

	d.	SO_4^2-						h.	K_2Cr_2O_7	

4.	Determine the oxidation of each element in (NH_4)_2CO_3

5.	The following reactions are not complete reactions. Determine if each of the following changes is an oxidation, a reduction, or neither:

	(a)	SO_3^2-  SO_4^2-				(b)	CaO  Ca		

	(c)	CrO_4^2-  Cr_2O_7^2-				(d)	2 I^-  I_2		

6.	For each of the following reactions, complete the summary table below the equation. If an element does not undergo any change, leave the last two columns blank. Also provide the formula of the oxidizing or reducing agent. An example is shown.

	a)	CuO + H_2  Cu + H_2O

element

Initial
Ox. No

Final
Ox. No.

e^- gained
or lost

Oxidized or reduced

Oxidizing or
Reducing Agent

Cu | +2 | | 0 | gain 2 | reduced | oxidizing agent - CuO
O | | | | | |
H | | | | | |

	b)	CH_4 + 2 O_2  CO_2 + 2 H_2O

element

Initial
Ox. No

Final
Ox. No.

e^- gained
or lost

Oxidized or reduced

Agent

C | | | | | |
H | | | | | |
O | | | | | |

	c)	2 Na(s) + Br_2(l)  2 NaBr(s)

element

Initial
Ox. No

Final
Ox. No.

e^- gained
or lost

Oxidized or reduced

Agent

Na | | | | | |
Br | | | | | |

	7.	Not all of the following reactions are redox reactions.  Place a check mark in the appropriate column for each reaction.

| | Redox | | Not Redox
a. | Na_2S(aq) + FeCl_2(aq)  2 NaCl(aq) + FeS(s) | | |
b. | 2 Na(s) + 2 H_2O(l)  2 NaOH(aq) + H_2(g) | | |
c. | 2 KClO_3(s)  2 KCl(s) + 3 O_2(g) | | |
d. | SO_2 + H_2O  H_2SO_3 | | |
e. | 2 Al + 6 HCl  2 AlCl_3 + 3 H_2 | | |

Unit 6: Redox Reactions & Electrochemistry	Assignment 1	Page  of