What are alloys?
Updated on May 31, 2025 | By Learnzy Admin
Alloys are mixtures of two or more metals, or a metal and a non-metal. They are made to improve the properties of metals, like making them stronger, harder, or resistant to rust.
Examples:
- Brass = Copper + Zinc
- Bronze = Copper + Tin
- Steel = Iron + Carbon
- Stainless Steel = Iron + Chromium + Nickel
- Solder = Lead + Tin
Why are alloys made?
- To make metals stronger
- To prevent rusting (corrosion)
- To improve hardness or appearance
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Metals and Non-metalsMore Questions on Metals and Non-metals
- Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).
- A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?
- Differentiate between metal and non-metal on the basis of their chemical properties.
- You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.
- Give reasons (a) Platinum, gold and silver are used to make jewellery. (b) Sodium, potassium and lithium are stored under oil. (c) Aluminium is a highly reactive metal, yet it is used to make utensils for cooking. (d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction.
- What type of oxides are formed when non-metals combine with oxygen?
- State two ways to prevent the rusting of iron.
- In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?
- Name two metals which will displace hydrogen from dilute acids, and two metals which will not.
- What are amphoteric oxides? Give two examples of amphoteric oxides.
- You are given a hammer, a battery, a bulb, wires and a switch. (a) How could you use them to distinguish between samples of metals and non-metals? (b) Assess the usefulness of these tests in distinguishing between metals and non-metals.
- Food cans are coated with tin and not with zinc because (a) zinc is costlier than tin. (b) zinc has a higher melting point than tin. (c) zinc is more reactive than tin. (d) zinc is less reactive than tin.
- An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be (a) calcium (b) carbon (c) silicon (d) iron.
- Which of the following methods is suitable for preventing an iron frying pan from rusting? (a) Applying grease (b) Applying paint (c) Applying a coating of zinc (d) All of the above
- Which of the following pairs will give displacement reactions? (a) NaCl solution and copper metal (b) MgCl₂ solution and aluminium metal (c) FeSO₄ solution and silver metal (d) AgNO₃ solution and copper metal
- What are alloys?
- Which metals do not corrode easily?
- What chemical process is used for obtaining a metal from its oxide?
- Name two metals which are found in nature in the free state.
- Define the following terms. (i) Mineral (ii) Ore (iii) Gangue
- Why do ionic compounds have high melting points?
- Show the formation of Na₂O and MgO by the transfer of electrons.
- Write the electron-dot structures for sodium, oxygen and magnesium.
- What would you observe when zinc is added to a solution of iron(II) sulphate? Write the chemical reaction that takes place.
- Which gas is produced when dilute hydrochloric acid is added to a reactive metal? Write the chemical reaction when iron reacts with dilute H₂SO₄.
- Write equations for the reactions of (i) iron with steam (ii) calcium and potassium with water
- Why is sodium kept immersed in kerosene oil?
- Explain the meanings of malleable and ductile
- Give an example of a metal which (i) is a liquid at room temperature. (ii) can be easily cut with a knife. (iii) is the best conductor of heat. (iv) is a poor conductor of heat.