Zadanie 3b
Pentane reacts with bromine, Br2, to form 2-bromopentane. (i) Explain, using equations, the initiation step and two propagation steps for this reaction. (ii) State one termination step for this reaction.
Homolytic fission and the initiation step
Explain how UV light or heat breaks a halogen molecule homolytically so that each atom keeps one electron, write the initiation equation with fish-hook arrows showing single-electron movement, and contrast homolytic with heterolytic fission.
Tę umiejętność sprawdza 12 zadań wzorowanych na arkuszach IB z lat 2024–2026.
Zadania sprawdzające tę umiejętność: 12 Otwórz w wyszukiwarce z filtrami
Zadanie 4c
Methane reacts with bromine gas in the presence of UV radiation to produce brominated hydrocarbons. (i) Explain, using an equation, how a bromine molecule undergoes homolytic fission. (ii) Using two equations, explain the propagation steps in the substitution…
Zadanie 4d
Ethane, C2H6, reacts with chlorine, Cl2, to produce chloroethane, C2H5Cl. Deduce the initiation step and two propagation steps for the mechanism of this reaction.
Zadanie 3a
Suppose carbonyl dibromide were made by a free-radical chain reaction of carbon monoxide, CO, with bromine vapour, Br2, started by ultraviolet light. The questions below treat this hypothetical route with the bond-enthalpy model. (i) Write an…
- Materiał graficzny
Zadanie 4d
Compound Y undergoes nucleophilic substitution with a hydroxide nucleophile. (i) Describe the movement of electron pairs during the reaction using curly arrows. (ii) Contrast homolytic and heterolytic fission of the C–Cl bond in compound Y. (iii) Explain,…
Zadanie 2b
(i) Oil of vitriol, spirit of hartshorn and wood alcohol are old trivial names still occasionally used for chemical substances, and names like these can be a source of confusion in international scientific communication. Outline how the modern system of naming…
- Materiał graficzny
Zadanie 3d
Chlorinated solvents such as tetrachloromethane, CCl4, and 1,1,1-trichloroethane, CH3CCl3, were once common in laboratories, but their production is now restricted by an international agreement. Besides climate change, state the specific…
Zadanie 29
Which radical is most likely to form when one covalent bond in bromochlorodifluoromethane, CBrClF2, is broken by ultraviolet light in the upper atmosphere? A. •CBrF2 B. •CClF2 C. •CBrClF D. •CBrClF2
Zadanie 29
Which species is formed when a chlorine molecule undergoes homolytic fission in the presence of ultraviolet radiation? A. A chlorine radical, Cl ⋅ B. A chloride ion, Cl− C. A chlorine cation, Cl+ D. An excited chlorine molecule, Cl2 ⋅
Zadanie 5a
(i) Write an equation for the homolytic fission of a bromine molecule under UV light, using curly arrows to show the movement of electrons. (ii) Under different conditions a bromine molecule can undergo heterolytic fission. Write an equation for this process,…
Zadanie 29
Methane reacts with chlorine in the presence of ultraviolet light. Two observations about this reaction are listed. - Observation 1: in the initiation step, Cl−Cl bonds undergo homolytic fission but C−H bonds do not. - Observation 2: the…
Zadanie 1b
Ethane reacts with bromine gas, Br2(g), in the presence of UV light to form bromoethane. (i) State the type of this reaction and the name of its mechanism. (ii) Explain the mechanism of this reaction by writing equations for one initiation step, two…