1. When magnesium reacts with hot water, it forms magnesium hydroxide and hydrogen gas. The reaction is more vigorous at higher temperatures. The hydrogen gas produced adheres to the surface of the magnesium, creating buoyant bubbles that make the metal rise and float on the water's surface. The increaRead more

    When magnesium reacts with hot water, it forms magnesium hydroxide and hydrogen gas. The reaction is more vigorous at higher temperatures. The hydrogen gas produced adheres to the surface of the magnesium, creating buoyant bubbles that make the metal rise and float on the water’s surface. The increased temperature accelerates the reaction, leading to a faster evolution of hydrogen gas and more buoyancy. The hydrogen bubbles displace water and reduce the overall density of the magnesium, causing it to rise. This floating phenomenon demonstrates the displacement of water by the evolved gas during the exothermic chemical reaction.

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  2. Burning in oxygen is not sufficient to determine the reactivity of metals like zinc, iron, copper, or lead because some metals may not exhibit a reaction under these conditions. Reactivity often involves the ability of metals to undergo specific chemical reactions, such as displacement reactions witRead more

    Burning in oxygen is not sufficient to determine the reactivity of metals like zinc, iron, copper, or lead because some metals may not exhibit a reaction under these conditions. Reactivity often involves the ability of metals to undergo specific chemical reactions, such as displacement reactions with acids or water. Metals like copper and lead may not react significantly with oxygen at normal temperatures, making combustion in oxygen alone an inadequate indicator of their reactivity. To comprehensively assess reactivity, it is essential to explore various reactions and conditions, such as acid reactions, to provide a more accurate evaluation of a metal’s chemical behavior.

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  3. Displacement reactions with acids can help establish the order of reactivity among metals like zinc, iron, copper, and lead. More reactive metals, such as zinc and iron, readily displace hydrogen from acids, producing metal salts and hydrogen gas. Copper, being less reactive, may undergo such reactiRead more

    Displacement reactions with acids can help establish the order of reactivity among metals like zinc, iron, copper, and lead. More reactive metals, such as zinc and iron, readily displace hydrogen from acids, producing metal salts and hydrogen gas. Copper, being less reactive, may undergo such reactions under specific conditions and with strong acids. Lead, being relatively unreactive, typically does not readily displace hydrogen from dilute acids. These displacement reactions provide valuable insights into the relative reactivity of metals, helping to establish an order based on their ability to displace hydrogen ions in acidic environments.

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  4. The reaction of potassium and sodium with water is highly exothermic and vigorous. When these alkali metals come into contact with water, they undergo a rapid reaction, forming metal hydroxides and releasing hydrogen gas. The metal hydroxide formed is water-soluble, creating an alkaline solution. ThRead more

    The reaction of potassium and sodium with water is highly exothermic and vigorous. When these alkali metals come into contact with water, they undergo a rapid reaction, forming metal hydroxides and releasing hydrogen gas. The metal hydroxide formed is water-soluble, creating an alkaline solution. The overall reaction for potassium (K) is:
    2K(s) + 2H₂O(l) → 2KOH(aq) + H₂(g)
    And for sodium (Na):
    2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g)

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  5. Calcium reacts less vigorously than potassium and sodium. The reaction is also less exothermic, producing a moderate amount of heat. The balanced chemical equation for the reaction of calcium (Ca) with water is: 2Ca(s) + 2H₂O(l) → 2Ca(OH)₂(aq) + H₂(g) Unlike the alkali metals, calcium does not produRead more

    Calcium reacts less vigorously than potassium and sodium. The reaction is also less exothermic, producing a moderate amount of heat. The balanced chemical equation for the reaction of calcium (Ca) with water is:
    2Ca(s) + 2H₂O(l) → 2Ca(OH)₂(aq) + H₂(g)
    Unlike the alkali metals, calcium does not produce a visible flame during the reaction. Additionally, calcium hydroxide (Ca(OH)₂) is sparingly soluble in water and forms a white precipitate, leading to the formation of a cloudy solution. Overall, the reactivity of calcium with water is intermediate between the highly reactive alkali metals and less reactive metals.

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