chemistry: the study of change -...
TRANSCRIPT
![Page 1: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/1.jpg)
Figure 1: In Greek mythology Sisyphus
was punished by being forced roll an
immense boulder up a hill, only to watch it
roll back down, and to repeat this action
forever. If this were a chemical reaction,
then it would never be observed, since the
reactants must overcome the energy
barrier to get to the other side (products).
http://chemwiki.ucdavis.edu/
13.4 활성화 에너지
![Page 2: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/2.jpg)
발열 반응(Exothermic Reaction)
흡열 반응(Endothermic Reaction)
활성화 에너지(activation energy, Ea ): 화학 반응이일어나는데 필요한 최소한의 에너지
A + B AB C + D++
활성복합체, 전이상태
반응과정 반응과정
퍼텐
셜에
너지
퍼텐
셜에
너지
![Page 3: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/3.jpg)
Ea 활성화 에너지 (J/mol)
R 기체 상수 (8.314 J/K•mol)
T 절대 온도
A 빈도 인자
아레니우스 식 (Arrhenius equation)
RTEaAek/
![Page 4: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/4.jpg)
아레니우스 식을 사용하여 다음의 이유를 설명하시오.
(a) 활성화 에너지가 증가하면 반응의 속도 상수가 감소한다.
(b) 온도가 증가하면 반응의 속도 상수가 증가한다.
![Page 5: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/5.jpg)
2 2H H H H 반응에 대한 퍼텐셜에너지 대반응 진행도의 그래프를 그리시오.
![Page 6: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/6.jpg)
Arrhenius 식의 선형 방정식
2개 온도 조건 T1과 T2
![Page 7: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/7.jpg)
![Page 8: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/8.jpg)
![Page 9: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/9.jpg)
![Page 10: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/10.jpg)
화학 반응에서 분자 배향(Molecular Orientation)의 중요성
유효한 충돌 생성물을 형성
유효하지 않은 충돌 생성물 형성하지 안음
![Page 11: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/11.jpg)
13.5 반응 메커니즘
2NO(g) + O2(g) 2NO2(g)
![Page 12: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/12.jpg)
길찾기:
공덕역 -> 중앙대후문
![Page 13: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/13.jpg)
2NO(g) + O2(g) 2NO2(g)
Mechanism:
![Page 14: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/14.jpg)
반응 메커니즘(Reaction mechanism):
생성물을 만드는 일련의 연속적인 기본 반응들
단계 1 : NO + NO N2O2
단계 2 : N2O2 + O2 2NO2
전체 반응 : 2NO + O2 2NO2
중간체(Intermediates):
반응 메커니즘의 기본 단계에서만 나타나고, 전체 화학 방정식에서는 나타나지 않음.
![Page 15: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/15.jpg)
단 분자 반응 A 생성물 속도 = k [A]
이 분자 반응 A + B 생성물 속도 = k [A][B]
이 분자 반응 A + A 생성물 속도 = k [A]2
반응의 분자도
반응의 분자도(molecularity of a reaction): 기본 반응의 각단계에서 반응하는 분자의 개수
* 단분자 반응(Unimolecular reaction): 한 분자가 참여하는 반응
* 이분자 반응(Bimolecular reaction ): 두 분자가 참여하는 반응
* 삼분자 반응(Termolecular reaction): 세 분자가 참여하는 반응
![Page 16: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/16.jpg)
속도 법칙과 반응의 기본 단계
• 메커니즘 속 기본 단계들의 조건:
(1) 기본 반응 단계를 합하면 반응에 대한 전체 균형 반응식이 나와야함
(2) 속도 결정 단계로 예측한 속도 법칙은 실험적으로 얻어진 속도법칙과 같아야 함
• 속도 결정 단계(rate-determining step): 생성물 형성에 관련된 여러단계 중에서 가장 느린 단계
기본 단계 : NO + NO N2O2
기본 단계 : N2O2 + O2 2NO2
전체 반응 : 2NO + O2 2NO2
![Page 17: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/17.jpg)
과산화수소 분해 반응
단계 1은 속도 결정 단계k1 = k
IO-는 중간체I-는 촉매
![Page 18: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/18.jpg)
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13.6 촉매 작용
2 /k pizzas year
20 /k pizzas year
![Page 21: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/21.jpg)
촉매(catalyst): 자기 자신은 반응에서 소모되지 않으면서 반응의 활성화에너지를 낮추어 줌으로써 화학 반응 속도를 증가시키는 물질
촉매 미사용 촉매 사용
속도촉매화 > 속도비촉매화
Ea < Ea′
RTEaeAk/
Ea k
T k
![Page 22: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/22.jpg)
불균일 촉매작용(heterogeneous catalysis) : 반응물과촉매가 서로 다른 상(phases)을 가짐.
• 암모니아의 하버 합성법
• 질산 제조의 오스트발트 공정(Ostwald process)
• 촉매 변환기(Catalytic converters)
균일 촉매작용(homogeneous catalysis) : 반응물과 촉매가보통 액체인 동일한 상(phase)을 가짐.
• 산 촉매
• 염기 촉매
• 효소 촉매
![Page 23: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/23.jpg)
N2(g) + 3H2(g) 2NH3(g)Fe/Al2O3/K2O
촉매
하버 공정(Haber Process)
![Page 24: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/24.jpg)
촉매 변환기
CO + 불완전 연소 탄화수소 + O2 CO2 + H2O촉매
변환기
2NO + 2NO2 2N2 + 3O2
촉매
변환기
![Page 25: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/25.jpg)
효소 촉매 작용(Enzyme Catalysis)
![Page 26: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/26.jpg)
효소 반응 속도
속도 = d[P]
dt
= k [ES]
Michaelis-Menten kinetics
max[ ][ ]
[ ]d
V Sd Pv
dt K S
![Page 27: Chemistry: The Study of Change - contents.kocw.netcontents.kocw.net/KOCW/document/2015/chungang/hanseungsu/3.pdf · Arrhenius 식의선형방정식 2개온도조건T 1과T 2. 화학반응에서분자배향(Molecular](https://reader036.vdocuments.mx/reader036/viewer/2022081409/6079f03dd2ae0d238128d1c8/html5/thumbnails/27.jpg)