§10.3 Chain Reaction 10.3.3 Brief history of chain reactions In 1918, after studying photochemistry, Nernst proposed the atomic chain reaction theory. It stated that when a reaction in which free atoms are formed that can decompose target molecules into more free atoms would result in a chain reaction Walther Hermann Nernst
Walther Hermann Nernst 10.3.3 Brief history of chain reactions § 10.3 Chain Reaction In 1918, after studying photochemistry, Nernst proposed the atomic chain reaction theory. It stated that when a reaction in which free atoms are formed that can decompose target molecules into more free atoms would result in a chain reaction
§10.3 Chain Reaction 10.3.4 rate equation of chain reaction Polymerization initiated by an initiator XX-2X● X·+RCH=CH2→> XRCH-CH2 XRCH-CH,·+RCH=CH2→XRCH-CH2-RCH-CH, k2 XR(CHCH2)n1CH-CH2·+RCH=CH2→>XR(CH-CH2)nCH-CH2· XR(CHCH2)nCH-CH2°+X·→>XR(CH-CH2)nCH-CH2X XR(CH-CH2)n+ XR(CH-CH2)m.+ XR(CH-CH),(CH-CH2)mRY 4 k2 k R / IR-CH-CH2JX-XP Just likes that of H2+Ch>
10.3.4 rate equation of chain reaction Polymerization initiated by an initiator X-X ⎯→2X • X • + RCH=CH2 → XRCH-CH2 • XRCH-CH2 • + RCH=CH2 → XRCH-CH2 -RCH-CH2 • …… XR(CH-CH2 )n-1CH-CH2 • + RCH=CH2 → XR(CH-CH2 )nCH-CH2 • XR(CH-CH2 )nCH-CH2 • +X • → XR(CH-CH2 )nCH-CH2X XR(CH-CH2 )n • + XR(CH-CH2 )m • → XR(CH-CH2 )n (CH-CH2 ) mRX k2 k3 1 1 2 1 2 2 2 3 [R-CH=CH ][X-X] k r k k = Just likes that of H2+Cl2 → k1 § 10.3 Chain Reaction
§10.3 Chain Reaction 10.3.4 rate equation of chain reaction For h+C1->2HCI =104-106 For H2+ Br 2HBr④=001 Cl,A→2Cl Brk,2Br Cl+H,k2>HCl+H. Br+H-k>HBr+H H+C1,k)HCI+Br.H+Br2-ks>HBr+Br 2Ck→Cl H+HBr-4→H2+Br 2Br5→Br
For H2+ Cl2⎯→ 2HCl = 104 ~ 106 For H2+ Br2 ⎯→ 2HBr = 0.01 10.3.4 rate equation of chain reaction § 10.3 Chain Reaction 1 2 3 4 2 2 2 2 Cl 2Cl Cl H HCl H H Cl HCl+Br 2Cl Cl k k k k ⎯⎯→ + ⎯⎯→ + + ⎯⎯→ ⎯⎯→ 1 2 3 4 5 2 2 2 2 2 Br 2Br Br H HBr H H Br HBr+Br H +HBr H +Br 2Br Br k k k k k ⎯⎯→ + ⎯⎯→ + + ⎯⎯→ ⎯⎯→ ⎯⎯→