อัตราการเกิดปฏิกิริยาเคมี pdf มหิดล

㹡��Դ��ԡ��ҷ�� ͧ�ա�ê��ѹ�ͧ͹��Ҥ�ͧ��÷��ҷӻ�ԡ��Ҩ֧��Դ�� 繻�ԡ��ҷ��Ѻ��͹ ��;�ѧ�ҹ��ѧ��ê��ѹ�ͧ͹��Ҥ�٧��Ҿ�ѧ�ҹ��͡��ѹ�� ԡ��ҹ�鹡��Ҩ��Դ��㹢�鹵͹�� ਹ (CN) 2 ��š��Դ��ê��ѹ��Դ�� C2 1 ��š�� N2 1 ��š��

�軯ԡ��Ҩӹǹ�ҡ �ѡ�ա�ê��ѹ��¢�鹨֧��Ե�ѳ�� ԡ��ҧ乵�ԡ�͡䫴� (NO) �Ѻ�͡��ਹ (O2)

�ҡ��֡�Ҿ�� N2O2 �Դ��㹢�зӻ�ԡ�� ʴ��ҡ�ê��Դ��§��鹵͹�� NO2 ��Դ��ҹ 2 ��鹵͹ �ѧ��

��¡��鹵͹��·��Դ�� ��ԡ�� (elementary reaction) ��ʴ��Դ��ԡ��дѺ��š��

��¡��ʴ��鹵͹��·��Դ��鹵��ӴѺ�� ��䡢ͧ��ԡ�� (reaction mechanism)

��¡ N2O2 ��Դ��㹻�ԡ�� ��Ѹ�ѹ�� (intermediate) ��¶֧��÷��Դ��㹻�ԡ��ҡ�� Ҩ�� Ѹ�ѹ��Դ㹢��á� ��Ƕ١��㹢�鹵�� 仢��㴢��˹��

�ӹǹ��š�Ţͧ��õ�駵�㹻�ԡ��¡�� ��š��Ե� (molecularity) �ͧ��кǹ��ù��
                   - ��㹻�ԡ��õ�駵鹷��Ǣ�ͧ��§ 1 ��š�� ¡��繡�кǹ��Ẻ˹��š�� (unimolecular)
                   - ��㹻�ԡ��õ�駵鹷��Ǣ�ͧ 2 ��š�� ¡��繡�кǹ��Ẻ�ͧ��š�� (bimolecular)
                   - ��㹻�ԡ��õ�駵鹷��Ǣ�ͧ 3 ��š�� ¡��繡�кǹ��Ẻ��š�� (termolecular)

��һ�ԡ��ҧ乵�ԡ�͡䫴� (NO) �Ѻ�͡��ਹ (O2) ��繡�кǹ��Ẻ�ͧ��š�� (bimolecular) ��з��ͧ��ԡ��õ�駵鹪��ѹ�ͧ��š��

㹡��֡�ҡ�䡡��Դ��ԡ��ҹ��Ҩ��ҡ��Ѵ�ѵ�ҡ��Դ��ԡ�� йӢ��Ҥ�Ҥ��ѵ��ѹ�Ѻ�ͧ��ԡ�� ¹�繡��ѵ�� Ǩ֧�ʹ͡�䡢ͧ��ԡ��ٻ�ͧ��ԡ�� ִ��ѡ�� 3 �� ѧ��

                   1. ��ԡ��·��ǵ�ͧ��ʴ��ԡ��
                   2. ��ԡ��·��Դ��鹪�ҷ��ش㹡�䡡��Դ��ԡ��ҷ��¡�� ��鹡�˹��ѵ�� (rate-determining step) ��鹨е�ͧ��顮�ѵ��͹�Ѻ��ѵ�ҷ��ҡ��÷��ͧ
                   3. ��ͧ��Ըա�õ�Ǩ�ͺ�� Ѹ�ѹ��㹻�ԡ��Т��Դ��鹨�ԧ

�͹��Ҵ٤��ѹ��ҧ��ѵ�ҡѺ��䡡��Դ��ԡ��ҡѹ��ҧ ��Ҩ��դ��ѹ��ѹ��ҧ��

��ҧ 1 (CH3)3CBr + OH- ---------> ( CH3)3COH + Br-

��ط��Դ�ҡ��ԡ�� ԡ��¢ͧ��ù��ͧ��ԡ��

��˵� :

㹤��繨�ԧ��ҧ�ѹ��оѹ�� 109.5 o (��ҧ�ѹ��оѹ�Тͧ CH4 �� 109.5 o ) ��͹�ѹ�ء��

��鹵͹�ͧ��Դ��ԡ��ҷ��Դ��鹵��ӴѺ�� 䡢ͧ��Դ��ԡ��ҹ��ͧ ��÷��Դ��㹻�ԡ��ҡ��¡�� Ѹ�ѹ�� ҹ��ö��׹�ѹ��ԧ �ѧ�� ҡ��ö�͡��㹻�ԡ��ҹ��Ѹ�ѹ��

��ԡ��¢��á�繢�鹷��Դ�� ¡�� 鹡�˹��ѵ�� Ф�� Ea �ͧ��Դ (CH3)3C+ �դ��٧ �֧�� (CH3)3C+ �Դ�� ǹ�ѵ�ҡ��Դ��ԡ��Ң�鹷��ͧ��鹨��ǡ��ҡ �ѧ��ѵ�ҡ��Դ��ԡ��Ңͧ��ԡ��Ѵ��֧�Ҩҡ�ѵ�ҡ��Դ��ԡ��Ңͧ��ԡ��㹢�鹷��˹�觹��ͧ

��ͷ��ͧ��ѵ�ҡ��Դ��ԡ�� 顮�ѵ�Ҵѧ��

rate = k [(CH3)3CBr]

�ʴ��ѵ�ҡ��Դ��ԡ��Ңͧ��鹡�˹��ѵ��ѵ�ҡ��Դ��ԡ��Ңͧ��ԡ��ҹ�� 繻�ԡ��ѹ�Ѻ 1 ��º�Ѻ�� (CH3)3CBr �� 繻�ԡ��ѹ�Ѻ 0 ��º�Ѻ OH- ��ѹ�Ѻ��ͧ��ԡ�� 1 ��ػ��ѵ�ҡ��Դ��ԡ��ҹ��Ѻ�� (CH3)3CBr ��§��Դ�� OH- ��ռŵ��ѵ�ҡ��Դ��ԡ��

�Ҷ֧�ç�� 繤��ʹ��ͧ�ѹ�ͧ��ѵ��С�䡡��Դ��ԡ�� 蹹��ͧ�Ҵٵ��ҧ��ͧ��º��º�Ѻ��ҧ��˹��

��ҧ 2 CH3CH2Br + OH- -------> CH3CH2OH + Br-

�ҡ��÷��ͧ�顮�ѵ�Ҵѧ��

rate = k [CH3CH2Br][OH-]

��͡��ѵ��蹹�� 䡢ͧ��ԡ��ҹ�Ҩ��͹��ᵡ��ҧ�ҡ��ҧ�á

�ӵͺ�� 䡢ͧ��ԡ��ҵ�ͧ��͹�Ѻ��ҧ�á��ҧ��͹ ��ԡ��Ҥ�è��Դ�ҡ��÷��÷��ͧ��Ҫ��ҷӻ�ԡ��ҡѹ�µç �ѧ��

��˵� :

㹤��繨�ԧ��ҧ�ѹ��оѹ�� 109.5 o (��ҧ�ѹ��оѹ�Тͧ CH4 �� 109.5 o ) ��͹�ѹ�ء��

��÷��¡��ҧ�ҹ�龺��Թ�� ¡��䡻�ԡ��ҷ��Դ��ѡɳТͧ��ҧ�� 1 �� SN1 (unimolecular nucleophilic substitution) ��е��ҧ�� 2 �� SN2 (bimolecular nucleophilic substitution)

�� ԡ��ҷ��ͧ��繻�ԡ��ҧ��û�Сͺ��Ť��(alkyl bromide)�Ѻ�δ�͡䫴��͹��͹�ѹ ��ա�䡡��Դ��ԡ��ҵ�ҧ�ѹ �ѧ�� ҵ�ͧ��÷��黯ԡ��㹵��ҧ�� 1 �Դ��Ǣ�� ҡ��õ�駵��㹡��鹢ͧ��Ф��鹢ͧ OH- ��ռŵ��ѵ�ҡ��Դ��ԡ��