Reactivity Series of Metals

• Reactivity series is the ranking of metals according to their reactivity from highest to lowest.
• The list of metals in the reactivity series from most reactive to least reactive is: Potassium, Sodium, Lithium, Calcium, Magnesium, Aluminium, Carbon, Zinc, Iron, Tin, Lead, Hydrogen, Copper, Silver, Gold, Platinum.
• Potassium, sodium, lithium, and calcium are highly reactive metals. They react with cold water to produce hydrogen and a metal hydroxide.
• Magnesium is a moderately reactive metal. It reacts with steam to produce hydrogen and a metal oxide. It will not react with cold water.
• Aluminium and zinc are relatively unreactive with cold water but will react with steam.
• Iron, tin, and lead do not react with water or steam but will react over time with oxygen in the air to form rust or tarnish.
• Copper, silver, gold and platinum are unreactive and are found in the Earth as metal ores or sometimes pure metals.
• Using a more reactive metal to displace a less reactive metal from its compound is called a displacement reaction.
• Electrolysis is used to extract the most reactive metals from their ores.

Prediction of Metal Reactions

• The reactivity series can be used to predict reactions between metals and acids, water or oxygen.
• Highly reactive metals like potassium and sodium react violently with acids, producing hydrogen gas and a salt.
• Less reactive metals like iron, zinc, and copper react more slowly with acids.
• Unreactive metals such as gold and platinum do not react with acids or oxygen.
• Exposure to water and oxygen causes corrosion in many metals, the rate of which depends on the metal's position in the reactivity series.

Applications, Advantages, and Disadvantages

• Knowledge of the reactivity series is used in the process of extracting metals from their ores.
• It helps in the selection of metals for specific purposes based on their reactivity.
• Reactive metals are used in batteries due to their ability to transfer electrons.
• Unreactive metals are used for jewellery and coating because of their resistance to rust and corrosion.
• However, the high reactivity of some metals makes them hazardous and should be handled with care, especially potassium and sodium.
• Unreactive metals often come at a higher cost due to their rarity and difficulty in extraction.

Extraction and Recycling of Metals

• Blast furnaces are used to extract iron from its ore using carbon, based on the principle of displacement in the reactivity series.
• Electrolysis is applied to extract reactive metals such as aluminium, sodium, and potassium from their ores.
• Less reactive metals like copper, silver, and gold are extracted from their ores by heating them in air, a process known as roasting.
• Recycling metals has many benefits: it saves energy, reduces landfill, conserves resources, and reduces the need for mining.