University:
Bradley University
Course:
CHM 116 | General Chemistry II
Academic year:

2023
Views:

479

Pages:

3
Author:

Cristian Santos

PAL – Week 10 (Mon/Tu) After Exam2 #15 EChem Part 1 (sec 18.1-18.2) Name Part A: Chem 1A review 1) Determine the oxidation number of the elements in each of the following compounds: a) H2CO3 b) N2 c) Zn(OH)4 2- 2) Identify the species being oxidized and reduced in each of the following reactions: + a) Cr (aq) + Sn b) 3 Hg 2+ 4+ (aq) (aq) + 2 Fe(s) + Cr 3+ (aq) + Sn 2+ 3 Hg2 (l) + 2 Fe - c) 3CuS (s) + 8H (aq) + 2NO3 (aq) (aq) 3+ 3Cu 2+ (aq) (aq) + 3S (s) + 4H2O (l) + 2NO(g) 1 Part B: Balancing Oxidation - Reductions under Acidic Conditions 3) Balance the redox reaction in acidic solution Fe 2+ - (aq) + MnO4 (aq) èFe 3+ (aq) + Mn 2+ (aq) Step 1) Assign oxidation numbers. Step 2) Separate the overall reaction into two half-reactions: one for oxidation and one for reduction. Oxidation: Reduction: Step 3) Balance each half-reaction with respect to mass (reminder: acidic conditions) Step 4) Balance each half reaction with respect to charge by adding electrons. Step 5, 6) Multiply the half reactions by a number to get the electrons to balance and add the two half reactions together Step 7) Double check! 2 Part C: Balancing Oxidation - Reductions under Basic Conditions 4) What is the difference between balancing a Redox reaction in a basic solution than in an acidic solution? Is there a difference? 5) Balance the following reaction occurring in basic solution - ClO (aq) +MnO2 (s) èMnO4 2- (aq) + Cl (aq) Step 1) Assign oxidation numbers. Step 2) Separate the overall reaction into two half-reactions: one for oxidation and one for reduction. Oxidation: Reduction: Step 3) Balance each half-reaction with respect to mass (tip: balance in acidic then basic conditions) Step 4) Balance each half reaction with respect to charge by adding electrons. Step 5, 6) Multiply the half reactions by a number to get the electrons to balance and add the two half reactions together Step 7) Double csheck! 3