T2V T4 C9

Which of the following processes increases the hardness of a metal?

• Purification

• Alloying

• Plating

• Polymerisation

Which of the following alloys is suitable for use in spoons and forks production?

• Brass

• Duralumin

• Cupronickel

• Stainless steel

Answer explanation

Stainless steel is ideal for spoons and forks due to its corrosion resistance, durability, and ease of cleaning. Other options like brass and duralumin are not suitable for food contact, while cupronickel is less common for cutlery.

What can a goldsmith do to make a gold ring harden?

• Add more gold

• Melted and re-moulded

• Tapped back to its original shape

• Re-melted and added with other elements.

Answer explanation

To harden a gold ring, a goldsmith can re-melt it and add other elements, such as alloys. This process increases the hardness and durability of the gold, unlike simply adding more gold or reshaping.

A substance contains the main component of silica. What is the substance?

• Alloy

• Glass

• Polymer

• Ceramic

Which polymer can be used to replace glass in industry?

• Bakelite

• Tiokol

• Perspex

• Neoprene

What are the elements that form duralumin?

• Iron, Silver

• Iron, Tin, Magnesium

• Zinc, Copper, Lead

• Copper, Magnesium, Aluminium

Why are ceramics used in the manufacture of artificial teeth?

• Soft and easy to shape

• Easy to shape and shiny

• Hard, strong and inert to chemicals

• Heat resistant and has low melting point

What should be done to natural rubber to produce tyres that are harder and more heat resistant?

• Add iron wire

• Heat with sulphur

• Add ethanoic acid

• Add ammonium solution

Which of the following can coagulate latex?

• Sulphur

• Soap Solution

• Lime Juice

• Sodium chloride

A rubber tapper found the latex had coagulated before reaching the factory. What can be done to avoid coagulation of the latex?

• Adding water into the latex

• Adding acid into the latex

• Keep latexs in close container

• Adding ammonia solution into the latexs.

Answer explanation

Adding ammonia solution to the latex helps prevent coagulation by stabilizing the proteins in the latex, keeping it in a liquid state until it reaches the factory. Other options may not effectively prevent coagulation.