Question
CHM 111 Exam 3 | Module 3 Fall 2017 Show All Work 1. Consider the following reaction in aqueous solution: 5Br(aq) + Br03-(aq) + 6H'(aq)- 3B6(ag) + 3H20(/) If the rate of disappearance of Br-(aq) at a particular moment during the reaction is 3.5 x 10-4M s-, what is the rate of appearance of Br2(aq) at that moment? 2. Calculate the equilibrium constant at 25°C for the following reaction 3. Calculate G-Antimony pentachloride decomposes at 448C. The reaction is: SbCl,(g)- SbCl,(g) + Cl,(g) An equilibrium mixture in a 5.00 L. flask at 448 °C contains 3.85 g of SbCls, 9.14 g of SbCls, and 2.84 g of Cl2. A certain reaction has a rate law of Rate k[AJ [B]o 4. What is the overall order of the reaction? 5. If the concentration of A is doubled, what is the reaction rate? 6. When the concentration of A and B are both 1.0M and the concentration of B is increased to 3.0M what would the rate of the reaction become? Consider the following reaction mechanism Step 1: 2N0 + H2 N2+H2O2 Step 2: H2O2 + H2 2H2O 7. What is the overall chemical reaction? 8. How many catalysts are in the reaction above? 9. How many intermediates are in the reaction above? 3
Explanation / Answer
Q1
if Br- dissapears at = 3.5*10^-4 M/s
the rate of formation is given by:
5 mol of Br- = 3 mol of Br2
3/5 mol ratio --> 3/5*3.5*10^-4 M/s = 0.00021 M/s = 2.1*10^-4 M/s Br2 forms
Q2
apply
dG = -RT*ln(K)
-9.2*10^3 = -8.314*298*lnK
K = exp(9200/(8.314*298))
K = 40.98