n ickel leung hau lam(32) lau ho yin(30) wong pui san(43) wang kwun sing(41) class: 5d
TRANSCRIPT
INTRODUCTION OF NICKEL
chemical element (Ni)
atomic number 28
silvery-white lustrous transition metal
hard and ductile
PHYSICAL PROPERTIESPhase solid
Density (at room temperature.) 8.908 g·cm−3
Liquid density (at atmospheric pressure) 7.81 g·cm−3
Melting point 1728 K, 1455 °C, 2651 °F
Boiling point 3186 K, 2913 °C, 5275 °F
Heat of fusion 17.48 kJ·mol−1
Heat of vaporization 377.5 kJ·mol−1
Molar heat capacity 26.07 J·mol−1·K
USAGES
corrosion-resistant -use for plating metals
nickel alloy
catalyst for hydrogenation
Enzymes of some microorganisms and plants contain nickel as an active center
USAGES electroplating and the manufacture
of alkaline batteries
Nickel metal is used in making alloys
(E.g. a "horseshoe magnet" made of alnico nickel alloy
The composition of alnico alloys is typically 8–12% Al, 15–26% Ni, 5–24% Co, up to 6% Cu, up to 1% Ti. )
APPLICATIONS Nickel is used to make Nickel aluminide
made up of nickel combined with several other metals including aluminium, chromium, molybdenum, zirconium and boron
Adding boron increases the ductility of the alloy and hardness
This alloy is extremely strong for its weight, five times stronger than stainless steel. Unlike most alloys, IC-221M increases in strength from room temperature up to 800 °C.
APPLICATIONS Nickel aluminide - has very high thermal
conductivity combined with high strength at high temperature -high strength and low density, used to coat blades in gas turbines and jet engines
APPLICATIONS Nickel is used in hydrogenation
Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst.
Hydrogenation typically constitutes the addition of pairs of hydrogen atoms to a molecule, generally an alkene. Catalysts are required for the reaction to be usable
APPLICATIONS substitute for decorative silver
making nickel-cadmium battery
The nickel–cadmium battery (commonly abbreviated NiCad or NiCad) is a type of rechargeable battery using nickel oxide hydroxide and metallic cadmium as electrodes.
APPLICATIONS A fully charged NiCad cell contains:
A nickel (IV) oxide-hydroxide positive electrode plate.
A cadmium negative electrode plate.
A separator.
An alkaline electrolyte (potassium hydroxide).
EQUATIONS The chemical reactions in a NiCad battery
during discharge are:
At the cadmium electrode:
At the nickel electrode:
The overall equation is