1-3 of 3 Results

  • Keywords: reductant x
Clear all

Chapter

Cover Making the Transition to University Chemistry

Transition Metals 2  

This chapter focuses on the first row of transition metals ranging from tin to copper. It clarifies how scandium and zinc are not transition metals due to their oxidation states and d subshells. The group has d-block elements with at least one stable ion that has a partially-filled d subshell. Transition metals showcase variable oxidation states. An acidic solution with a reductant can reduce a transition metal ion, while an alkaline solution with an oxidant could oxidize a transition metal. The stability of the high oxidation states can be significantly increased in alkaline solutions. The chapter also notes how transition metals are often used as catalysts.

Book

Cover Oscillations, Waves, and Chaos in Chemical Kinetics
Oscillations, Waves, and Chaos in Chemical Kinetics shows how these ‘exotic’ patterns arise from the underlying chemical mechanisms. The phenomena of oscillations, travelling waves, and chaos in reacting chemical systems began as curiosities but now support an active, international research field. The origin of ‘chemical feedback’ is revealed using three example reactions: the iodate-reductant (Landolt) reaction, the Belousov–Zhabotinsky reaction, and the combustion of hydrogen. Thermal feedback is also discussed. These mechanisms lead to clock reactions and travelling reaction fronts, thermal runaway, and flames; to oscillations and excitability; to target patterns, spiral and scroll waves; to bistability, ignition, extinction, and hysteresis; and to complex oscillations and chaos in flow reactors. These phenomena are related to important processes in biology, including the development of cardiac arrhythmias, nerve signal transmission, and animal coat patterning.

Chapter

Cover Oscillations, Waves, and Chaos in Chemical Kinetics

Clocks and fronts  

This chapter provides a background on the clock reaction discovered by Hans Heinrich Landolt in 1886, which involves the autocatalytic iodate-bisulphite system. It examines the related phenomena of clock reactions and clock waves in a wide range of systems from gas to solid phases, and into biology. It also mentions the iodate-reductant system which can be simulated using empirical rate-law forms. The chapter describes clock-type behaviour in solution phase reactions, such as gas-phase reactions. These involve the oxidation of simple hydrocarbon. The chapter explains that long induction periods arise in clock reactions associated with thermal runaway. It cites sudden ignition of haystacks as a well-known example of a thermal explosion. It includes a form of clock reaction behaviour observed in the polymerization of a mutant form of haemoglobin.