Burning Calcium Archives | School Portal NG

The following experiments show the reaction of metals with Oxygen and air. Burning Magnesium Procedure (a) Cut a 2cm length piece of magnesium ribbon. Using a pair of tongs introduce it to a Bunsen flame. Remove it when it catches fire. Observe. Place the products in a beaker containing about 5cm3 of water. Test the solution/mixture using litmus papers (b)Cut another 2cm length piece of magnesium ribbon. Using a pair of tongs introduce it to a Bunsen flame. When it catches fire, lower it slowly into a gas jar containing Oxygen. Place about 5cm3 of water into the gas jar. Test the solution/mixture using litmus papers. Test the solution/mixture using litmus papers Observations (a) In air Magnesium burns with a bright blindening flame in air forming white solid/ash /powder. Effervescence/bubbles/ fizzing Pungent smell of urine. Blue litmus paper remains blue. Red litmus paper turns blue (b) In pure Oxygen Magnesium burns faster with a very bright blindening flame pure oxygen forming white solid/ash /powder. No effervescence/bubbles/ fizzing. No pungent smell of urine. Blue litmus paper remains blue. Red litmus paper turns blue Explanation Magnesium burns in air producing enough heat energy to react with both Oxygen and Nitrogen to form Magnesium Oxide and Magnesium nitride. Both Magnesium Oxide and Magnesium nitride are white solid/ash /powder. Chemical equations Magnesium + Oxygen ->Magnesium Oxide 2Mg(s) + O2(g) -> 2MgO(s) Magnesium + Nitrogen ->Magnesium Nitride 3Mg(s) + N2(g) ->Mg3N2 (s) Magnesium Oxide dissolves in water to form a basic/alkaline solution of Magnesium hydroxide Chemical equations MagnesiumOxide + Water ->Magnesium hydroxide 2Mg(s) + O2(l) -> 2MgO(s) Magnesium Nitride dissolves in water to form a basic/alkaline solution of Magnesium hydroxide and producing Ammonia gas. Ammonia is also an alkaline/basic gas that has a pungent smell of urine. Chemical equations Magnesium Nitride + Water ->Magnesium hydroxide + Ammonia gas Mg3N2 (s)+ 6H2O (l) -> 3Mg(OH)2(aq) + 2NH3(g) Burning Sodium Procedure (a) Carefully cut a very small piece of sodium. Using a deflagrating spoon introduce it to a Bunsen flame. Remove it when it catches fire. Observe. Place the products in a beaker containing about 20cm3 of water. Test the solution/mixture using litmus papers (b) Carefully cut another very small piece of sodium. Using a deflagrating spoon introduce it to a Bunsen flame. When it catches fire, lower it slowly into a gas jar containing Oxygen. Place about 20 cm3 of water into the gas jar. Test the solution/mixture using litmus papers. Test the solution/mixture using litmus papers Observations (a) In air Sodium burns with a yellow flame in air forming a black solid. Blue litmus paper remains blue. Red litmus paper turns blue (b) In pure Oxygen Sodium burns faster with a golden yellow flame in pure oxygen forming a yellow solid. Effervescence/bubbles/ fizzing. Gas produced relights glowing splint. Blue litmus paper remains blue. Red litmus paper turns blue. Explanation (a)Sodium burn in air forming black Sodium Oxide Chemical equations Sodium + Oxygen/air -> Sodium Oxide 4Na(s) + O2(g) -> 2Na2O(s) Sodium Oxide dissolves in water to form a basic/alkaline solution of Sodium hydroxide Chemical equations Sodium Oxide + Water ->Sodium hydroxide Na2O(s) + H2O (l) -> 2NaOH(aq) (b)Sodium burns in pure oxygen forming yellow Sodium peroxide Chemical equations Sodium + Oxygen -> Sodium peroxide 2Na(s) + O2(g) -> Na2O2 (s) Sodium peroxide dissolves in water to form a basic/alkaline solution of Sodium hydroxide. Oxygen is produced. Chemical equations Sodium Oxide + Water -> Sodiumhydroxide + Oxygen 2Na2O2 (s) + 2H2O (l) -> 4NaOH(aq) + O2 (l) III. Burning Calcium Procedure (a)Using a pair of tongs hold the piece of calcium on a Bunsen flame. Observe. Place the products in a beaker containing about 2cm3 of water. Test the solution/mixture using litmus papers (b)Using a pair of tongs hold another piece of calcium on a Bunsen flame. Quickly lower it into a gas jar containing Oxygen gas .Observe. Place about 2cm3 of water.Swirl. Test the solution/mixture using litmus papers Observations (a)In air Calcium burns with difficulty producing a faint red flame in air forming a white solid. Blue litmus paper remains blue. Red litmus paper turns blue (b) In pure Oxygen Calcium burns with difficulty producing a less faint red flame Oxygen forming a white solid. Blue litmus paper remains blue. Red litmus paper turns blue Explanation (a)Calcium burns in air forming white calcium Oxide. Calcium Oxide coat/cover the calcium preventing further burning. Chemical equations Calcium + Oxygen/air -> calcium Oxide 2Ca(s) + O2(g) -> 2CaO(s) Small amount of Calcium Oxide dissolves in water to form a basic/alkaline solution of Calcium hydroxide. The common name of Calcium hydroxide is lime water. Chemical equations Calcium Oxide + Water ->Calcium hydroxide CaO(s) + H2O (l) -> Ca(OH)2 (aq) Burning Iron Procedure (a)Using a pair of tongs hold the piece of Iron wool/steel wire on a Bunsen flame. Observe. Place the products in a beaker containing about 2cm3 of water. Test the solution/mixture using litmus papers (b)Using a pair of tongs hold another piece of Iron wool/steel wire on a Bunsen flame. Quickly lower it into a gas jar containing Oxygen gas . Observe. Place about 2cm3 of water. Swirl. Test the solution/mixture using litmus papers Observations (a) In air Iron wool/steel wire burns producing a Orange flame in air forming a brown solid. Blue litmus paper remains blue. Red litmus paper turns faint blue (b) In pure Oxygen Iron wool/steel wire burns producing a golden Orange flame in Oxygen forming a Brown solid. Blue litmus paper remains blue. Red litmus paper turns faint blue Explanation (a)Iron burns in air forming brown Iron(III) Oxide Chemical equations Iron + Oxygen/air -> Iron(III)Oxide 4Fe(s) + 3O2(g) -> 2Fe2O3(s) Very small amount of Iron(III)Oxide dissolves in water to form a weakly basic/alkaline brown solution of Iron(III) hydroxide. Chemical equations Calcium Oxide + Water ->Iron(III)hydroxide Fe2O3(s) + 3H2O (l) ->2Fe(OH)3 (s) Burning Copper Procedure (a)Using a pair of tongs hold the piece of copper turnings/shavings on a Bunsen flame. Observe. Place the products in a beaker containing about 2cm3 of water. Test the solution/mixture using litmus papers (b)Using a pair of tongs hold another piece of Copper turnings/shavings on a Bunsen flame. Quickly lower it into a gas jar containing Oxygen gas . Observe. Place about 2cm3 of water. Swirl. Test the solution/mixture using litmus papers Observations (a) In air Copper turnings/shavings burns with difficulty producing a green flame in air forming a black solid. Blue litmus paper remains blue. Red litmus paper turns faint blue (b) In pure Oxygen Copper turnings/shavings burns less difficulty producing a green flame in Oxygen forming a Brown solid. Blue litmus paper remains blue. Red litmus paper turns faint blue Explanation (a)Copper burns in air forming black Copper(II) Oxide Chemical equations Copper + Oxygen/air -> Copper(II)Oxide 2 Cu(s) + O2(g) -> 2CuO(s) Very small amount of Copper(II)Oxide dissolves in water to form a weakly basic/alkaline blue solution of Copper(II) hydroxide. Chemical equations Copper(II) Oxide + Water -> Copper(II)hydroxide CuO(s) + H2O (l) ->Cu(OH) 2 (s) See also: USES OF OXYGEN OXYGEN THE ATMOSPHERE PROPERTIES OF ACIDS INTRODUCTION TO ACIDS, BASES AND INDICATORS

REACTION OF METALS WITH OXYGEN/AIR