CHE 102LLR Study Guide - Midterm Guide: Rate-Determining Step, Alcohol By Volume, Breathalyzer
31 May 2018
School
Department
Course
Professor
Chemistry 102
1
REVIEW QUESTIONS
Test 1
1. Hydrogen iodide decomposes at 800 K via a second-order process to produce hydrogen and iodine
according to the following chemical equation.
2 HI (g) H2 (g) + I2 (g)
At 800 K it takes 142 seconds for the initial concentration of HI to decrease from 6.75 × 10-2 M to
3.50 × 10-2 M. What is the rate constant for the reaction at this temperature?
2. The equilibrium constant is given for one of the reactions below. Determine the value of the
missing equilibrium constant.
H2 (g) + Br2 (g) 2 HBr (g) Kc = 3.8 × 104
4 HBr (g) 2 H2 (g) + 2 Br2 (g) Kc = ?
3. The reaction below has a Kp value of 41. What is the value of Kc for this reaction at 400 K?
N2(g) + 3 H2(g) 2 NH3(g)
2
4. The first-order reaction, SO2Cl2 SO2 + Cl2, has a half-life of 8.75 hours at 593 K. How long
will it take for the concentration of SO2Cl2 to fall to 16.5% of its initial value?
5. In aqueous solution, hypobromite ion, BrO-, reacts to produce bromate ion, BrO3-, and
bromide ion, Br-, according to the following chemical equation:
3 BrO-(aq) BrO3-(aq) + 2 Br-(aq)
A plot of 1/[BrO-] vs. time is linear and the slope is equal to 0.056 M-1s-1. If the initial
concentration of BrO- is 0.80 M, how long will it take one-half of the BrO- ion to react?
6. The reaction that occurs in a Breathalyzer, a device used to determine the alcohol level in a
person's bloodstream, is given below. If the rate of appearance of Cr2(SO4)3 is 1.64 M/min at a
particular moment, what is the rate of disappearance of C2H6O at that moment?
2 K2Cr2O7 + 8 H2SO4 + 3 C2H6O 2 Cr2(SO4)3 + 2 K2SO4 + 11 H2O
Document Summary
Test 1: hydrogen iodide decomposes at 800 k via a second-order process to produce hydrogen and iodine according to the following chemical equation. 2 hi (g) h2 (g) + i2 (g) At 800 k it takes 142 seconds for the initial concentration of hi to decrease from 6. 75 10-2 m to. 3. 50 10-2 m. what is the rate constant for the reaction at this temperature: the equilibrium constant is given for one of the reactions below. Determine the value of the missing equilibrium constant. H2 (g) + br2 (g) 2 hbr (g) 4 hbr (g) 2 h2 (g) + 2 br2 (g) Kc = : the reaction below has a kp value of 41. , and bromide ion, br-, according to the following chemical equation: 2: consider the following reaction and its equilibrium constant: 4 cuo(s) + ch4(g) co2(g) + 4 cu(s) + 2 h2o(g) A reaction mixture contains 0. 22 m ch4, 0. 67 m co2 and 1. 3 m h2o.
H2(g) + I2(g). At equilibrium it is found that [HI] = 3.53 × 10-3 M, [H2] = 4.79 × 10-4 M, and [I2] = 4.79 × 10-4 M. What is the value of Kc at this temperature?
