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Aluminum, zinc and tin all react with sodium hydroxide solution to form
salts and hydrogen gas
Advantages of using plastics
Can be colored so can be made to look attractive
Easy to clean
Can be recycled
Most methods of preventing rusting involve?
coating the iron or mild steel with something that stops it coming into contact with moisture and air.
The salt formed depends on?
which acids is used
what is amphoteric?
meaning that it reacts with acid and alkali.
Less reactive metals will only react with
dilute nitric acid
in this case a different gas is formed
Metals may react with non-metals and with reagents such as
acids and alkalis
Corrosion is the process by which metals or alloys are converted to.....
one their compounds by chemical activity
Copper reacts with the gases in damp air to form a green substance called
verdigris
Rather than attempt to remove the aluminum oxide, sometimes the layer is made thicker by a process called?
anodizing
Air consists of about of oxygen?
20%
Silver does not react with oxygen because it is?
too unreactive
Non-metals have the following properties
They are poor thermal conductors
Some non-metals have very high melting points.
Corrosion produces a layer of oxide or another compound on the surface of the metal which spoils its appearance and forms what is called
tarnish
It is known that some metals ions have a negative effect on the human body.
Toxicity of aluminum
Disposing of waste plastics is problematic. If they are burnt they will produce?
unpleasant gases that can cause air pollution.
what is the Reactions of metals with water or steam formula?
metal + steam → metal oxide + hydrogen
Plastics do not occur naturally. They are made by people using?
using chemicals obtained from natural gas and crude oil
The chemical reactions which bring about corrosion are difficult to reverse. This means that the metal must be cleaned by rubbing off the compound. This process is called?
abrasion
Does tin and copper have similar chemistry?
they both have the similar chemistry but tin is a little more reactive.
Most metals react with oxygen to form?
oxides
When steam is passed over hot iron wool
what is formed?
black iron oxide is formed
Reactive metals will react with dilute acids to form?
metals salts and hydrogen gas
when does dry oxidation occur?
this occurs when the metal corrodes in a water-free environment, such as the oxidation of aluminum to form the protective aluminum oxide layer.
when is Painting done?
it is done by applying one or more coats of an enamel base paint to the clean metal surface.