CH302 Homework 10-solutions - Bodet(ngb299 Homework 10 sutclie(51630 This print-out should have 20 questions Multiple-choice questions may continue on

# CH302 Homework 10-solutions - Bodet(ngb299 Homework 10...

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Bodet (ngb299) – Homework 10 – sutcli ff e – (51630) 1 This print-out should have 20 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. This is the LAST homework!! 001 10.0 points NOTE In this question you must consider the 1/a term mentioned in class. Consider the reaction below. Which of the following is a correct expression of the rate? 1 2 S 8 ( s ) + 3 O 2 ( g ) -→ 2 SO 3 ( g ) 1. - Δ [O 2 ] 3 · Δ t correct 2. 2 · Δ [SO 3 ] Δ t 3. - 4 · Δ [S 8 ] Δ t 4. - Δ [SO 3 ] 2 · Δ t 5. Δ [O 2 ] 3 · Δ t Explanation: rate = - Δ [O 2 ] 3 · Δ t = Δ [SO 3 ] 2 · Δ t 002 10.0 points Consider the concentration-time dependence graph for two first-order reactions. [A] 0 Molar Concentration of Reactant Concentration -→ Time -→ Which reaction has the larger rate con- stant? 1. the reaction represented by the lower curve correct 2. Unable to determine 3. the reaction represented by the upper curve Explanation: 003 (part 1 of 2) 10.0 points For BOTH the next questions you MUST consider the 1/a term in the rate equation for species A, etc. A ”unique rate” means ’average rate’ taking into account the stoi- chiometric coe ffi cients. In the reaction 3 ClO - (aq) 2 Cl - (aq) + ClO - 3 (aq) the rate of reaction of Cl - is 3 . 6 mol L · min . What is the rate of reaction of ClO - ? 1. 2 . 7 mol L · min 2. 5 . 4 mol L · min correct 3. 0 . 9 mol L · min 4. 10 . 8 mol L · min 5. 1 . 8 mol L · min Explanation: rate of change of [ClO - ] = 3 . 6 mol Cl - L · min 3 mol ClO - 2 mol Cl - = 5 . 4 mol L · min 004 (part 2 of 2) 10.0 points What is the unique rate of the reaction? 1. 2 . 7 mol L · min 2. 10 . 8 mol L · min
Bodet (ngb299) – Homework 10 – sutcli ff e – (51630) 2 3. 5 . 4 mol L · min 4. 0 . 9 mol L · min 5. 1 . 8 mol L · min correct Explanation: The unique rate is given by rate of change g species coe ffi cient g species For this reaction the unique rate is 1 2 × 3 . 6 mol L · min = 1 . 8 mol L · min 005 10.0 points If the rate of reaction increases by a factor of 2.3 when the concentration of reactant in- creases by a factor of 1.5, what is the order of the reaction with respect to this reactant?

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• Fall '07
• Holcombe
• Chemical reaction, Rate equation, 0.111 M, 0.112 m