November 9
Please read pg 286-289
questions #1, 2, 3, 4, 6, 7, 8, 9
Ted-ed All the energy in the universe is..... https://youtu.be/dmcevC55K3s
Ted-ed What triggers a chemical reaction? https://youtu.be/8m6RtOpqvtU
Periodic Table of Videos: Exothermic https://youtu.be/c-iisqNh1r8
Periodic Table of Videos: Endothermic https://youtu.be/H5Q2jkVDzeQ
November 10
Energy Changes in Chemical Reactions
Ted Ed What is a calorie? https://youtu.be/VEQaH4LruUo
Energy Changes in Chemical Reactions
Ted Ed What is a calorie? https://youtu.be/VEQaH4LruUo
November 18
Solutions on calorimetry problems
Solutions on Hess's law problems
December 1
Extra problems Rates Temp and Potential Energy
Solutions to Problem Set are here: first part - second part
Extra problems Rates Temp and Potential Energy
Solutions to Problem Set are here: first part - second part
December 2
Catalysis and Problem Set
Catalysis Clip https://youtu.be/A_PhvIktMOw
Review Answers
Part 1
Answers:
1. 4.21 g 2. -85.0 kJ/mol 3. 1.9 x 102 kJ 4. 46 kJ/mol 5. (omit) 8. a) neutron b) nitrogen-13
Part 2
Answers:
1. a) r = k[O2][NO]2 b) 12x c)85.2 M/s d) i) 1st order ii) 2nd order iii) 3rd order
2 a) r = k[CH3)3CBr] b) 3x c) 3.0 x 10-3 M/s d) i) 1st b) 0th c) 1st
Part 3
Answers:
Answers:
1. a) Fastest (e- tranfer only) b) or d) Slowest (bonds are broken in solid copper)
2. a) 0.48 mol/h b) 0.20 mol/min 3 a) directly n) directly c) inversely
5. a) r = k[A]2[B]3 b) Rate increases 72-fold c) 5
6. 1 cm x 1cm x 1cm 7. 9.6 x 10-5 M/s
Answers to Catalyst Problems:
Part 1:
1. Nature of Reactants, Concentration, Surface Area, Temperature, Catalyst
2. Surface Area is the only one that applies to heterogeneous systems. Ex. magnesium ribbon and acid would be slower than magnesium powder and acid.
3. Qualitatively the rate would increase. Quantitatively the rate would increase by a factor of 4 because it would most likely double for every increase of 10oC.
4. The coal dust has a much larger surface area for the oxygen to react with in this combustion reaction which leads to the explosion that can occur. The lump of coal has a lower surface area making it harder to react with the oxygen in the air and thus is much safer. **Think about the lycopodium powder demonstration that was done in class.**
5. The factor involved in these warnings is concentration. The high concentration of oxygen leads to the combustion reaction occurring explosively fast.
Part 2:
3. a) 60kJ
b) -35 kJ
c) step 1, reactants→W, since it has the highest activation energy it is most likely to be the slowest step.
d) exothermic
e) V, X, Z
f) W, Y
Part 3:
1. i) Increasing collision frequency – Temperature, Surface Area, Concentration
ii) Increasing the fraction of collisions that are effective – Nature of Reactants, Temperature, Concentration, Catalyst
2. a) 2 H2 (g) + O2 (g) → 2 H2O (g) This reaction does not likely occur as a single step because the activation energy is very high. By the addition of a catalyst that causes the reaction to occur in multiple steps we can reduce the activation energy and cause this reaction to occur faster.
b) 2 H2 (g) + 4 Pt (s) → 4 Pt-H
4 Pt-H + O2 (g) → 2 H2O (g) + 4 Pt (s)
3. a) heterogeneous catalyst
b) homogeneous catalyst
c) homogeneous catalyst
d) heterogeneous catalyst
4. a) The reaction with the Fe2+ ions is faster because it will always collide with the correct orientation thus there will be a higher number of effective collisions. The reaction involving oxalate ions will occasionally collide with the incorrect orientation thus the reaction will not occur.
b) The steel wool has a higher surface area so according to collision theory this will increase the number of collisions which will cause the reaction to occur faster.
c) The solid pill that is taken will have particles with a lower amount of energy than the particles in the liquid state. Thus when they collide they will be less likely to react. So this reaction with the solid pill is safe because the fraction of effective collisions is lower.
5. a) Cl2 (g) + H2 (g) → 2 HCl (g)
b) Cl (g) , H (g)
c) The reaction involving the molecular form of both reactants is much slower than the reaction involving the atomic chlorine with molecular hydrogen. The reaction of molecular chlorine with molecular hydrogen will have a higher activation energy since it is seen to be a slower reaction.
Catalysis and Problem Set
Catalysis Clip https://youtu.be/A_PhvIktMOw
Review Answers
Part 1
Answers:
1. 4.21 g 2. -85.0 kJ/mol 3. 1.9 x 102 kJ 4. 46 kJ/mol 5. (omit) 8. a) neutron b) nitrogen-13
Part 2
Answers:
1. a) r = k[O2][NO]2 b) 12x c)85.2 M/s d) i) 1st order ii) 2nd order iii) 3rd order
2 a) r = k[CH3)3CBr] b) 3x c) 3.0 x 10-3 M/s d) i) 1st b) 0th c) 1st
Part 3
Answers:
Answers:
1. a) Fastest (e- tranfer only) b) or d) Slowest (bonds are broken in solid copper)
2. a) 0.48 mol/h b) 0.20 mol/min 3 a) directly n) directly c) inversely
5. a) r = k[A]2[B]3 b) Rate increases 72-fold c) 5
6. 1 cm x 1cm x 1cm 7. 9.6 x 10-5 M/s
Answers to Catalyst Problems:
Part 1:
1. Nature of Reactants, Concentration, Surface Area, Temperature, Catalyst
2. Surface Area is the only one that applies to heterogeneous systems. Ex. magnesium ribbon and acid would be slower than magnesium powder and acid.
3. Qualitatively the rate would increase. Quantitatively the rate would increase by a factor of 4 because it would most likely double for every increase of 10oC.
4. The coal dust has a much larger surface area for the oxygen to react with in this combustion reaction which leads to the explosion that can occur. The lump of coal has a lower surface area making it harder to react with the oxygen in the air and thus is much safer. **Think about the lycopodium powder demonstration that was done in class.**
5. The factor involved in these warnings is concentration. The high concentration of oxygen leads to the combustion reaction occurring explosively fast.
Part 2:
3. a) 60kJ
b) -35 kJ
c) step 1, reactants→W, since it has the highest activation energy it is most likely to be the slowest step.
d) exothermic
e) V, X, Z
f) W, Y
Part 3:
1. i) Increasing collision frequency – Temperature, Surface Area, Concentration
ii) Increasing the fraction of collisions that are effective – Nature of Reactants, Temperature, Concentration, Catalyst
2. a) 2 H2 (g) + O2 (g) → 2 H2O (g) This reaction does not likely occur as a single step because the activation energy is very high. By the addition of a catalyst that causes the reaction to occur in multiple steps we can reduce the activation energy and cause this reaction to occur faster.
b) 2 H2 (g) + 4 Pt (s) → 4 Pt-H
4 Pt-H + O2 (g) → 2 H2O (g) + 4 Pt (s)
3. a) heterogeneous catalyst
b) homogeneous catalyst
c) homogeneous catalyst
d) heterogeneous catalyst
4. a) The reaction with the Fe2+ ions is faster because it will always collide with the correct orientation thus there will be a higher number of effective collisions. The reaction involving oxalate ions will occasionally collide with the incorrect orientation thus the reaction will not occur.
b) The steel wool has a higher surface area so according to collision theory this will increase the number of collisions which will cause the reaction to occur faster.
c) The solid pill that is taken will have particles with a lower amount of energy than the particles in the liquid state. Thus when they collide they will be less likely to react. So this reaction with the solid pill is safe because the fraction of effective collisions is lower.
5. a) Cl2 (g) + H2 (g) → 2 HCl (g)
b) Cl (g) , H (g)
c) The reaction involving the molecular form of both reactants is much slower than the reaction involving the atomic chlorine with molecular hydrogen. The reaction of molecular chlorine with molecular hydrogen will have a higher activation energy since it is seen to be a slower reaction.
