ChE102 - Tutorial 10 Solutions.pdf - ChE102 Chemistry for...

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ChE102 Chemistry for Engineers - Tutorial 10 Solutions Solve the following problems either individually or in small groups (3 students maximum). Submit one copy of the solutions per group. Ask the TA for help if you need assistance solving the problems. Note: This tutorial covers content from all of electrochemistry. If your instructor has not finished the electrochemistry unit you may not be able to complete all questions. Your TA will let you know which problems you are expected to complete. Solutions to this tutorial will be available on LEARN at 4:30 PM on Friday, Dec. 1 st . Problem 1 Identify whether the following reactions are redox reactions and balance the reactions appropriately. a) SiCl 4 (aq) → SiO 2 (s) + Cl - (aq) (basic media) b) As 2 O 3 (s) + NO 3 - (aq) → H 3 AsO 4 (aq) + NO(g) (acidic media) O
Step 3: add H 2 O to balance oxygen As 2 O 3 (s) + 5H 2 O(l) 2H 3 AsO 4 (aq) NO 3 - (aq) → NO(g) + 2H 2 O(l) Step 4: add H + to balance hydrogen As 2 O 3 (s) + 5H 2 O(l) → 2H 3 AsO 4 (aq) + 4H + (aq) NO 3 - (aq) + 4H + (aq) → NO(g) + 2H 2 O(l) Step 5: balance charge by adding e - As 2 O 3 (s) + 5H 2 O(l) → 2H 3 AsO 4 (aq) + 4H + (aq) + 4 e - NO 3 - (aq) + 4H + (aq) + 3 e - → NO(g) + 2H 2 O(l) Step 6: balance number of e - for each half-reaction add the two half-reactions 3 x (As 2 O 3 (s) + 5H 2 O(l) → 2H 3 AsO 4 (aq) + 4H + (aq) + 4 e - ) 4 x (NO 3 - (aq) + 4H + (aq) + 3 e - → NO(g) + 2H 2 O(l)) Overall: 3As 2 O 3 (s) + 4NO 3 - (aq) + 16H + (aq) + 15H 2 O(l) → 6H 3 AsO 4 (aq) + 4NO(g) + 8H 2 O(l) + 12H + (aq) Simplify the reaction: 3As 2 O 3 (s) + 4NO 3 - (aq) + 4H + (aq) + 7H 2 O(l) 6H 3 AsO 4 (aq) + 4NO(g) Problem 2 Given the following data: E ° (V) Cu + (aq) + e - Cu (s) 0.522 Cu 2+ (aq) + 2e - Cu (s) 0.340 Cu 2+ (aq) + e - Cu + (aq) 0.158 2H + (aq) + 2e - H 2 (g) 0.00 Identify whether each of the following statements is TRUE or FALSE.

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