n ickel leung hau lam(32) lau ho yin(30) wong pui san(43) wang kwun sing(41) class: 5d

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NICKEL Leung Hau Lam(32) Lau Ho Yin(30) Wong Pui San(43) Wang Kwun Sing(41) Class: 5D

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NICKEL Leung Hau Lam(32)Lau Ho Yin(30) Wong Pui San(43) Wang Kwun Sing(41)Class: 5D

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

~END~