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State two ways to prevent the rusting of iron.
There are two ways to prevent the rusting of iron: Coating with a protective layer: Iron can be protected from rusting by applying a coating of paint, oil, or grease. These coatings act as a barrier between the iron and the surrounding environment, preventing moisture and oxygen from coming into conRead more
There are two ways to prevent the rusting of iron:
Coating with a protective layer: Iron can be protected from rusting by applying a coating of paint, oil, or grease. These coatings act as a barrier between the iron and the surrounding environment, preventing moisture and oxygen from coming into contact with the iron surface.
Galvanization: Galvanization is a method of protecting iron from rusting by coating it with a thin layer of zinc. This process forms a protective barrier on the surface of the iron, preventing the corrosive elements from reaching the iron and causing rust. Even if the zinc coating gets damaged, the iron underneath remains protected.
These methods effectively prevent the rusting of iron and help to maintain its durability and appearance.
p. 17 (49-60)
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p. 18
What type of oxides are formed when non-metals combine with oxygen?
Types of Oxides Formed by Non-Metals When non-metals combine with oxygen, they form oxides that can be classified into two types: acidic oxides and neutral oxides. Acidic Oxides: Non-metals such as sulfur, nitrogen, and carbon combine with oxygen to form acidic oxides. These oxides dissolve in waterRead more
Types of Oxides Formed by Non-Metals
When non-metals combine with oxygen, they form oxides that can be classified into two types: acidic oxides and neutral oxides.
Acidic Oxides: Non-metals such as sulfur, nitrogen, and carbon combine with oxygen to form acidic oxides. These oxides dissolve in water to produce acidic solutions. For example, sulfur dioxide (SO2) and nitrogen dioxide (NO2) are acidic oxides that dissolve in water to form sulfurous acid (H2SO3) and nitric acid (HNO3) respectively.
Neutral Oxides: Non-metals like carbon monoxide (CO) and nitrous oxide (N2O) form neutral oxides. These oxides do not show any acidic or basic properties when dissolved in water. They neither produce acidic nor alkaline solutions.
It is important to note that not all non-metals react with oxygen to form oxides. For example, noble gases like helium, neon, and argon do not readily combine with oxygen to form oxides.
p. 5
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p. 4
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
Reasons for using platinum, gold, and silver to make jewellery: Platinum, gold, and silver are highly valued for their beauty and rarity, making them ideal for creating luxurious and precious jewellery pieces. These metals are also known for their durability and resistance to tarnish, ensuring thatRead more
Reasons for using platinum, gold, and silver to make jewellery:
Platinum, gold, and silver are highly valued for their beauty and rarity, making them ideal for creating luxurious and precious jewellery pieces.
These metals are also known for their durability and resistance to tarnish, ensuring that the jewellery retains its shine and appearance over time.
Reasons for storing sodium, potassium, and lithium under oil:
Sodium, potassium, and lithium are highly reactive metals that can react vigorously with air and moisture in the atmosphere.
Storing these metals under oil helps to prevent their exposure to air and moisture, which can lead to oxidation and the formation of unwanted compounds.
Reasons for using aluminium to make utensils for cooking:
Despite being a highly reactive metal, aluminium forms a protective oxide layer on its surface when exposed to air.
This oxide layer prevents further reaction with air or food, making aluminium a suitable choice for cooking utensils due to its light weight, good thermal conductivity, and resistance to corrosion.
Reasons for converting carbonate and sulphide ores into oxides during extraction:
Carbonate and sulphide ores are usually less stable and more difficult to reduce directly to obtain the desired metal.
See lessBy converting these ores into oxides through processes like roasting and calcination, it becomes easier to reduce the metal oxides to obtain the pure metal during the extraction process.
p. 18
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.
Lemon or tamarind juice is effective in cleaning tarnished copper vessels due to their acidic nature. The sour substances contain citric acid in lemon juice and tartaric acid in tamarind juice. These acids react with the tarnish on the copper surface, which is usually a layer of copper oxide, and heRead more
Lemon or tamarind juice is effective in cleaning tarnished copper vessels due to their acidic nature. The sour substances contain citric acid in lemon juice and tartaric acid in tamarind juice. These acids react with the tarnish on the copper surface, which is usually a layer of copper oxide, and help to dissolve it. The acidic properties of lemon or tamarind juice help to remove the tarnish and restore the shine of the copper vessels.
p. 8
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Differentiate between metal and non-metal on the basis of their chemical properties.
Chemical Properties of Metals: Metals have certain chemical properties that distinguish them from non-metals. Reaction with Oxygen: Metals react with oxygen to form metal oxides. These oxides are generally basic in nature. For example, when iron reacts with oxygen, it forms iron oxide (Fe2O3), whichRead more
Chemical Properties of Metals:
Metals have certain chemical properties that distinguish them from non-metals.
Reaction with Oxygen: Metals react with oxygen to form metal oxides. These oxides are generally basic in nature. For example, when iron reacts with oxygen, it forms iron oxide (Fe2O3), which is a basic oxide.
Reaction with Water: Some metals react with water to form metal hydroxides and release hydrogen gas. This reaction is more prominent with alkali metals like sodium and potassium. For example, when sodium reacts with water, it forms sodium hydroxide (NaOH) and releases hydrogen gas.
Reaction with Acids: Metals react with acids to form metal salts and release hydrogen gas. The reactivity of metals with acids varies. For example, zinc reacts with hydrochloric acid to form zinc chloride (ZnCl2) and releases hydrogen gas.
Displacement Reactions: Metals can displace other metals from their salt solutions. A more reactive metal can displace a less reactive metal from its salt solution. This displacement reaction is based on the reactivity series of metals.
Chemical Properties of Non-metals:
Non-metals also have distinct chemical properties that set them apart from metals.
Reaction with Oxygen: Non-metals react with oxygen to form non-metal oxides. These oxides are generally acidic or neutral in nature. For example, when carbon reacts with oxygen, it forms carbon dioxide (CO2), which is an acidic oxide.
Reaction with Water: Non-metals generally do not react with water. However, some non-metals like chlorine and bromine can react with water under specific conditions.
Reaction with Acids: Non-metals do not react with acids to produce hydrogen gas. Instead, they may react with acids to form different compounds depending on the specific non-metal and acid involved.
Electronegativity: Non-metals have a higher electronegativity compared to metals. This means that non-metals have a greater tendency to gain electrons and form negative ions.
Metals and non-metals exhibit different chemical properties. Metals tend to form basic oxides, react with water and acids, and can displace other metals from their salt solutions. Non-metals, on the other hand, form acidic or neutral oxides, have limited reactivity with water and acids, and have a higher electronegativity.
See lessA 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?
The solution used by the man to bring back the glitter of the old and dull gold bangles is likely to be a corrosive and fuming liquid. This is because the solution was able to dissolve the gold and reduce its weight drastically. It is important to note that such a solution is one of the few reagentsRead more
The solution used by the man to bring back the glitter of the old and dull gold bangles is likely to be a corrosive and fuming liquid. This is because the solution was able to dissolve the gold and reduce its weight drastically. It is important to note that such a solution is one of the few reagents that can dissolve gold and platinum. Aqua regia, a mixture of concentrated hydrochloric acid and concentrated nitric acid, is an example of such a solution.
p. 8 (52-63)
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Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).
Reasons why copper is used to make hot water tanks and not steel (an alloy of iron): Corrosion Resistance: Copper is highly resistant to corrosion, especially in hot water environments. It forms a protective oxide layer that prevents further corrosion, making it ideal for hot water tanks. Heat ConduRead more
Reasons why copper is used to make hot water tanks and not steel (an alloy of iron):
Corrosion Resistance: Copper is highly resistant to corrosion, especially in hot water environments. It forms a protective oxide layer that prevents further corrosion, making it ideal for hot water tanks.
Heat Conductivity: Copper has excellent thermal conductivity, which means it can efficiently transfer heat. This property allows hot water to be quickly and evenly distributed throughout the tank, ensuring efficient heating.
Ductility and Malleability: Copper is a highly ductile and malleable metal, making it easy to shape and form into the desired tank design. This flexibility allows for the creation of custom shapes and sizes to fit specific hot water tank requirements.
Lightweight: Copper is relatively lightweight compared to steel, making it easier to handle and install. This is particularly advantageous when dealing with large hot water tanks that need to be transported and maneuvered during installation.
Longevity: Copper has a long lifespan and can withstand high temperatures without losing its structural integrity. This durability ensures that copper hot water tanks can provide reliable service for many years.
Overall, the combination of corrosion resistance, heat conductivity, ductility, malleability, lightweight, and longevity makes copper the preferred choice for hot water tanks over steel (an alloy of iron).
p. 18
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Which metals do not corrode easily?
There are certain metals that do not corrode easily. These metals have a high resistance to oxidation and are therefore less prone to corrosion. Some examples of metals that do not corrode easily include gold, platinum, and silver. These metals are known for their high chemical stability and are oftRead more
There are certain metals that do not corrode easily. These metals have a high resistance to oxidation and are therefore less prone to corrosion. Some examples of metals that do not corrode easily include gold, platinum, and silver. These metals are known for their high chemical stability and are often used in jewelry and other decorative items. Additionally, stainless steel is another metal that is highly resistant to corrosion due to the presence of chromium in its composition. It forms a protective layer of chromium oxide on its surface, which prevents further oxidation and corrosion.
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What chemical process is used for obtaining a metal from its oxide?
The chemical process used for obtaining a metal from its oxide is reduction. In this process, the metal oxide is heated with a suitable reducing agent, such as carbon or a more reactive metal, to remove the oxygen and obtain the pure metal. For example, when zinc oxide (ZnO) is heated with carbon (CRead more
The chemical process used for obtaining a metal from its oxide is reduction. In this process, the metal oxide is heated with a suitable reducing agent, such as carbon or a more reactive metal, to remove the oxygen and obtain the pure metal. For example, when zinc oxide (ZnO) is heated with carbon (C), it is reduced to metallic zinc (Zn) and carbon monoxide (CO) gas is produced. This reduction process is commonly used to obtain metals from their compounds.
p. 15
See lessName two metals which are found in nature in the free state
Gold and silver are two metals that are found in nature in the free state. p. 14 p. 13
Gold and silver are two metals that are found in nature in the free state.
p. 14
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