magnesium ribbon experiment class 10

Burning of magnesium ribbon in air - Lab Work

To carry out the burning of magnesium ribbon in air and classify it as physical or chemical changes.

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Burning of magnesium ribbon in Chemical Reactions and Equations – Class 10 Science Experiment

Chapter name: chemical reactions and equations, activity name:   burning of magnesium ribbon in chemical reactions and equations, activity description:.

This experiment demonstrates the chemical reaction between magnesium and oxygen, resulting in the formation of magnesium oxide. It also illustrates the release of heat energy during the combustion of magnesium.

Required Items:

• Magnesium ribbon (about 3 cm long)
• Pair of tongs
• Spirit lamp or burner

Step by Step Procedure:

• Take a small piece (about 3 cm long) of magnesium ribbon.
• Rub the magnesium ribbon with sandpaper to remove any oxide layer on its surface.
• Hold the cleaned magnesium ribbon with a pair of tongs to keep a safe distance from the flame during the experiment.
• Use a spirit lamp or burner to ignite the magnesium ribbon.

Experiment Observations:

When you burn the magnesium ribbon, you will observe the following:

• The magnesium ribbon burns with a dazzling white flame.
• The magnesium ribbon undergoes a chemical reaction with oxygen in the air.
• The magnesium ribbon changes into a white powder, which is magnesium oxide.
• There will be a release of enormous amount of heat energy during the combustion.

Precautions:

• Handle the magnesium ribbon with tongs to avoid direct contact with the flame.
• Perform the experiment in a well-ventilated area to prevent the buildup of fumes.
• Keep a safe distance from the burning magnesium to avoid any accidents.
• Do not look directly at the intense white flame, as it may harm your eyes.

Lesson Learnt from Experiment:

Through this experiment, we learn that magnesium can react with oxygen to form magnesium oxide, which is an example of a chemical combination reaction. Additionally, we observe that such reactions release a significant amount of heat energy.

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Burning of a Magnesium Ribbon

To analyse the chemical reaction of burning of magnesium ribbon in air.

This experiment aims to study the combination reaction between metal (magnesium) and oxygen. Magnesium forms magnesium oxide on burning in the presence of air. It is a combination reaction between two elements. Magnesium oxide is basic in nature; thus, its aqueous solution turns red litmus blue. 

2Mg(s) + O 2 (g) → 2MgO(s)

In this experiment, apparatus and materials are required: A pair of tongs, a burner, a pair of goggles, a watch glass, a beaker, a piece of sandpaper, magnesium ribbon (2 to 3 cm long), red and blue litmus papers, and distilled water.

Experiment Procedure

To perform this experiment, steps to be followed in the following manner:

• Take a magnesium ribbon (2 to 3 cm long) and clean it with sandpaper. This will remove the oxide layer deposited over the magnesium ribbon, which makes it passive. 
•  Hold the magnesium ribbon with a pair of tongs over a watch glass and burn it in the air with a burner. Watch the burning of magnesium ribbon using a pair of dark goggles.
• Collect the white powder obtained on the watch glass.
• Transfer and mix the white powder in a beaker containing a small amount of distilled water. 
• Put drops of this mixture over the red and blue litmus papers and record your observations.

From this experiment, we have learnt that when a white-coloured magnesium ribbon is heated in the air, it burns with a white dazzling white flame and forms a white powder chemically known as magnesium oxide. 

When the formed product, that is, magnesium oxide, reacts with water, it produces magnesium hydroxide, which is basic in nature. 

FAQs on Burning of a Magnesium Ribbon

Q1: what is the combination reaction.

Answer: A reaction in which two or more reactants combine to form a single product is known as a combination reaction. Example: 2Na(s) + Cl 2 (g) → 2NaCl(s)

Q2: What is the balanced equation for the reaction between magnesium and oxygen?

Answer: The balanced equation is: 2Mg(s) + O 2 (g) → 2MgO(s)

Q3: What is the colour of the flame when magnesium burns in the air?

Answer: Magnesium burns with a dazzling white flame.

Q4: What is the effect of magnesium hydroxide on litmus paper?

Answer: Magnesium hydroxide is basic in nature. Testing magnesium hydroxide with litmus paper turns red litmus to blue.

Q5: What is the oxidation state of magnesium in MgO?

Answer: The oxidation state of magnesium in MgO is +2.

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Class  10 Science- Chapter 1- Chemical Reactions and Equations- Activity 1.1 Burning of a Magnesium Ribbon in air

The “Burning Magnesium Ribbon” activity in the chemistry curriculum of Class 10 demonstrates a fundamental chemical process known as a combination reaction. This experiment involves the reaction of magnesium metal with oxygen from the air to form magnesium oxide, a new compound, showcasing how elements combine to form more complex substances.

Activity 1.1 Burning of a Magnesium Ribbon in air

Materials Needed:

• Magnesium ribbon: A thin strip of magnesium metal that serves as the reactant.
• Safety equipment: Protective goggles, lab coat, and gloves to ensure safety from the intense light and heat produced.
• Ignition source: A Bunsen burner or a matchstick to ignite the magnesium ribbon.
• A container or a clamp to hold the magnesium ribbon.

Steps of the Activity:

• Preparation: Clean the magnesium ribbon with sandpaper to remove any oxide layer, ensuring a more vigorous reaction.
• Ignition: Hold the magnesium ribbon with tongs or a clamp and ignite it using the Bunsen burner or matchstick, keeping it at a safe distance to avoid the bright light harming the eyes.
• Observation: Watch as the magnesium burns with a brilliant white light, forming white ash, which is magnesium oxide.

Also Check – Why should a magnesium ribbon be cleaned before burning in air?

What to Look For:

• The intense white light and heat indicate the exothermic nature of the reaction.
• The white ash formed, which is magnesium oxide, showing the transformation from a metal to an oxide.

Why It Happens:

• The reaction is an example of oxidation, where magnesium loses electrons to oxygen, forming MgO. This is a combination reaction where two elements combine to form a single product.

Importance of the Activity:

• Demonstrates the principle of combination reactions in chemistry.
• Highlights the concept of oxidation and reduction.
• Engages with the conservation of mass principle, as the mass of magnesium and oxygen before the reaction equals the mass of magnesium oxide produced.

This activity not only illustrates the chemical reaction process but also emphasises safety in chemical experimentation, the conservation of mass, and the transformation of substances at a molecular level, making it a comprehensive educational experience.

Also Check – Chapter 1 – A Detailed Guide to “Chemical Reactions and Equations” Activities for Class 10 Students

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The change in mass when magnesium burns

In association with Nuffield Foundation

• Four out of five

Students weigh magnesium and heat it in a crucible, noting the change in weight they can discover the formula for magnesium oxide

Video support and linked resources

This experiment is included in our Conservation of mass video, along with supporting resources , including illustrated technician notes ,  integrated instructions ,  worksheets, a structure strip and more. 

The practical activity takes around 30–45 minutes, depending on the competence of the class. Students should all be standing and should wear eye protection. Students with long hair should tie it back.

It is a good idea for students to practice lifting the lid on and off the crucible and the crucible off the pipe clay triangle before they start. This has the added bonus of checking that all the tongs are functioning correctly.

To enable students to light their Bunsen burners they will need access to matches or lighters. Alternatively, light one or two Bunsen’s around the room and students can light their own using a splint.

The most significant hazard in this experiment is the hot apparatus. Warn students that it will take some time to cool down.

For classes with shorter attention spans, the final step of heating to constant mass could be omitted.

• Eye protection.
• Access to a balance (2 decimal places)
• Crucible with lid
• Pipe clay triangle
• Bunsen burner
• Heat resistant mat
• Emery paper (optional)
• Magnesium ribbon, about 10–15 cm

Health, safety and technical notes

• Read our standard health and safety guidance
• Wear eye protection. 
• Magnesium ribbon, Mg(s) – see CLEAPSS Hazcard HC059a . Fresh, clean magnesium is best for this experiment. If the magnesium is tarnished then emery or sand paper will be required to clean it.

Source: Royal Society of Chemistry

The apparatus and set up required to calculate the change on mass when magnesium burns

• Cut a piece of magnesium about 10–15 cm long. If it is looking tarnished or black then clean it using the emery paper. Twist it into a loose coil.
• Weigh the crucible with the lid (mass 1) and then the magnesium inside the crucible with the lid (mass 2).
• Set up the Bunsen burner on the heat resistant mat with the tripod. Place the pipe clay triangle over the tripod in a Star of David formation, ensuring that it is secure. Place the crucible containing the magnesium in the pipe clay triangle and put the lid on.
• Light the Bunsen burner and begin to heat the crucible. It is best to start with a gentle blue flame, but you will need to use a roaring flame (with the air hole fully open) to get the reaction to go.
• Once the crucible is hot, gently lift the lid with the tongs a little to allow some oxygen to get in. You may see the magnesium begin to flare up. If the lid is off for too long then the magnesium oxide product will begin to escape. Don’t let this happen.
• Keep heating and lifting the lid until you see no further reaction. At this point, remove the lid and heat for another couple of minutes. Replace the lid if it appears that you are losing some product.
• Turn off the Bunsen burner and allow the apparatus to cool.
• Re-weigh the crucible with lid containing the product (mass 3).
• Heat the crucible again for a couple of minutes and once again allow to cool. Repeat this step until the mass readings are consistent. This is known as heating to constant mass.

Teaching notes

Students should have recorded the following masses:

• mass 1 = crucible + lid
• mass 2 = crucible + lid + magnesium 
• mass 3 = crucible + lid + product

This should allow them to calculate the mass of the mass of the magnesium (mass 2 – mass 1) and the mass of the product (mass 3 – mass 1). They could also calculate the increase in mass (mass 3 – mass 2), which corresponds to the mass of oxygen.

The equation is:

• Magnesium + oxygen → magnesium oxide
• 2Mg + O 2  → 2MgO

Students sometimes get unconvincing results to this experiment. It is worth evaluating what they have done as there are several reasons why their results may be disappointing:

• the magnesium oxide product may escape as they lift the lid
• not all the magnesium may have reacted (the product may still look a bit grey rather than white)
• they may have prodded the product with their splint so not all of it got weighed (more common than you might expect)
• not taring the balance correctly when measuring the mass 
• having the magnesium coiled too tightly so that not all of it reacts

Finding the formula of magnesium oxide

• To find the formula of magnesium oxide, students will need the mass of the magnesium and the mass of the oxygen. They will also require the relative atomic masses. Magnesium is 24 and oxygen is 16.
• They should divide mass by the atomic mass for each element. The gives the number of moles of each.
• Having done this for both elements, they should find the ratio between the two by dividing them both by the smallest number.
• The ratio should be close to 1:1 as the formula of magnesium oxide is MgO.
• Mass magnesium = 2.39 g
• Mass magnesium oxide = 3.78 g
• So mass oxygen = 1.39 g
• Number moles Mg = 2.39/24 = 0.0995
• Number moles O = 1.39/16 = 0.0868
• Divide by the smallest to give the ratio aproximately 1 Mg : 1 O
• This would suggest a formula of MgO, which is the correct formula

A graph showing the mass of the magnesium and the mass of oxygen which has combined with it. The x axis is the mass of magnesium in grams and the y axis is the mass of oxygen in grams. The line representing the formula MgO, a 1:1 ratio.

• Students will need the mass of the magnesium and the mass of oxygen which has combined with it. You will need a copy of the graph for the class.
• All students plot their masses of magnesium and oxygen onto the graph. The majority of the class’ results should fall on or near the line representing the formula MgO, a 1:1 ratio. This helps to show clearly any anomolous results and should help to convince students who are disappointed by a 1:1.25 ratio, for instance, that the correct formula really is MgO.

More resources

Add context and inspire your learners with our short career videos showing how chemistry is making a difference .

Additional information

This is a resource from the  Practical Che mistry project , developed by the Nuffield Foundation and the Royal Society of Chemistry.

Practical Chemistry activities accompany  Practical Physics  and  Practical Biology .

© Nuffield Foundation and the Royal Society of Chemistry 

• 11-14 years
• 14-16 years
• Practical experiments
• Equations, formulas and nomenclature

Specification

• 1.7.4 convert the given mass of a substance to the amount of the substance in moles (and vice versa) by using the relative atomic or formula mass; and
• 1.7.13 determine the empirical formulae of simple compounds and determine the moles of water of crystallisation present in a hydrated salt from percentage composition, mass composition or experimental data; and
• 2.6.4 determine the empirical formulae of simple compounds and determine the moles of water of crystallisation present in a hydrated salt from percentage composition, mass composition or experimental data;
• Students should be able to: calculate empirical formula from data giving composition by mass or percentage by mass.
• 5 i. be able to use experimental data to calculate: empirical formulae. Calculations of empirical formula may involve composition by mass or percentage composition by mass data.
• c) calculations of empirical and molecular formulae, from composition by mass or percentage compositions by mass and relative molecular mass
• Some reactions may appear to involve a change in mass but this can usually be explained because a reactant or product is a gas and its mass has not been taken into account.
• Students should be able to explain any observed changes in mass in non-enclosed systems during a chemical reaction given the balanced symbol equation for the reaction and explain these changes in terms of the particle model.
• The balancing numbers in a symbol equation can be calculated from the masses of reactants and products by converting the masses in grams to amounts in moles and converting the numbers of moles to simple whole number ratios.
• Use a balanced equation to calculate masses of reactants or products.
• Recall and use the law of conservation of mass.
• Explain any observed changes in mass in non-enclosed systems during a chemical reaction and explain them using the particle model.
• 1.47b Explain the law of conservation of mass applied to: a non-enclosed system including a reaction in an open flask that takes in or gives out a gas
• 1.48 Calculate masses of reactants and products from balanced equations, given the mass of one substance
• C5.3.1 recall and use the law of conservation of mass
• C5.3.2 explain any observed changes in mass in non-enclosed systems during a chemical reaction and explain them using the particle model
• C5.3.7 use a balanced equation to calculate masses of reactants or products
• C5.3.13 suggest reasons for low yields for a given procedure
• C1.3i recall and use the law of conservation of mass
• C1.3j explain any observed changes in mass in non-enclosed systems during a chemical reaction and explain them using the particle model
• C1.3l use a balanced equation to calculate masses of reactants or products
• C5.2.1 recall and use the law of conservation of mass
• C5.2.2 explain any observed changes in mass in non-enclosed systems during a chemical reaction and explain them using the particle model
• C5.2.7 use a balanced equation to calculate masses of reactants or products
• C1.3k recall and use the law of conservation of mass
• C1.3l explain any observed changes in mass in non-enclosed systems during a chemical reaction and explain them using the particle model
• C1.3n use a balanced equation to calculate masses of reactants or products
• Given a balanced equation, the mass or number of moles of a substance can be calculated given the mass or number of moles of another substance in the reaction
• (p) how to calculate the formula of a compound from reacting mass data
• (d) how empirical and molecular formulae can be determined from given data

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• Preparatory

Question Video: Identifying the Correct Observation When Magnesium Is Burned in Air Science • First Year of Preparatory School

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What do you observe on burning magnesium in air?

Video Transcript

What do you observe on burning magnesium in air? (A) A liquid is formed. (B) A white powder is formed. (C) A gas evolves. (D) A solid that is bendable and bright is formed.

Since this question is asking us to identify what is observed when magnesium is burned in the air, let us first discuss what occurs in this chemical reaction.

In any chemical reaction, chemicals that start the chemical reaction are called reactants. And chemicals that are formed during the chemical reaction are called products. Reactants are separated from the products with an arrow, which means “reacts to produce.”

In this question, one of the reactants is magnesium, which is burned. Magnesium is a silver metal usually found as a ribbon, since it is malleable. In order for a chemical reaction to occur, magnesium must react with something in the air, but what? The magnesium reacts with the oxygen gas in the air when the magnesium is burned. When this chemical reaction occurs, magnesium oxide is formed as the product. When this chemical reaction occurs, the silver ribbon begins to change into a white powder substance. Eventually, all of the magnesium ribbon will react with the oxygen in the air and only the white powder remains. This white powder is the product, magnesium oxide.

Now that we have discussed this chemical reaction, let us take a look at our answer choices. We can see that answer choice (B) matches the description of the product, magnesium oxide. Therefore, a white powder is formed when observing the burning magnesium in air.

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Why should a magnesium ribbon be cleaned before burning in air?

The magnesium ribbon should be cleaned before burning in the air because the layer of magnesium oxide (which is formed due to the reaction of magnesium with air ) can be removed in order to get the desired chemical reaction. also in order to remove the oxide layer, the presence of which slowdowns the oxidation process. so, by cleaning it, the burning process takes place easily..

Why should magnesium ribbon be cleaned before burning in air ?

Why a magnesium

ribbon should be cleaned before burning?

Why should a magnesium ribbon be cleaned before it is burnt in air?

Why should magnesium ribbon be cleaned before burning in air?

Is it because it reacts with CO 2 or with O 2 in the air?

• Chemistry Practicals
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• Class 9 to Carry out the Reaction of Burning of Magnesium Ribbon in air and Classify Them as Physical or Chemical Changes

Chemistry Practical Class 9 To carry out the reaction of Burning of magnesium ribbon in air and classify it as physical or chemical changes Viva Questions with Answers

Q1. Define Physical Changes.

Answer. A physical change occurs when there is no change in the composition of a substance and no change in the chemical nature of the substance.

The interconversion of state occurs during physical change.

SOLID ⇄ LIQUID ⇄ GAS

Q2. Define Chemical Changes.

Answer. It is a change that causes a change in the chemical properties of matter, resulting in the formation of a new substance. As an example, consider the burning of oil or fuel.

Heat is evolved or taken in, the formation of bubbles, gas, and fumes, as well as a change in the colour of the reactants, can take place when they form a product.

Reactants → Products

A + B → C (Chemical reaction)

Q3. What is a Chemical Reaction?

Answer. A chemical reaction is a chemical change in which the bonds are broken within reactant molecules, and new bonds are formed within product molecules in order to form a new substance. A chemical reaction can be represented by a chemical equation, which specifies the number and type of atoms involved, as well as their arrangement into molecules or ions. The element symbols are used as a shorthand notation for the elements in a chemical equation, with arrows indicating the direction of the reaction.

Q4 How many types of chemical reactions are there?

Answer . There are 4 types of chemical reactions. They are as follows-

• Combination Reaction
• Decomposition Reaction
• Displacement Reaction
• Double Displacement Reaction

Q5. Define Combination reaction.

Answer. A reaction in which two or more reactants combine to form a single product is known as a combination reaction. It takes the form of X + Y → XY

Combination reaction is also known as a synthesis reaction.

Example of combination reaction: 2Na + Cl 2 → 2NaCl

Q6. Define Decomposition Reaction.

Answer. A reaction in which a single compound breaks into two or more simpler compounds is known as a decomposition reaction.

It takes the form of XY → X + Y

A decomposition reaction is just the opposite of a combination reaction.

Example of a decomposition reaction: CaCO 3 → CaO + CO 2

Q7. Define Displacement Reaction.

Answer. A chemical reaction in which a more reactive element displaces a less reactive element from its aqueous salt solution. It takes the form X + YZ → XZ + Y

It is also called a substitution reaction

Example of displacement reaction: Zn + CuSO 4 → ZnSO 4 + Cu

Q8. Define Double Displacement Reaction.

Answer. A chemical reaction in which ions get exchanged between two reactants which form a new compound is called a double displacement reaction. It takes the form of XY + ZA → XZ + YA

It is also called a metathesis reaction

Example of a double displacement reaction:

BaCl 2 + Na 2 SO 4 → BaSO 4 + 2NaCl

Q9. What is the formula of Magnesium?

Answer. The formula of Magnesium is Mg.

Q10. Give the reaction between magnesium and oxygen?

Answer. Magnesium reacts with oxygen to form magnesium oxide.

Q11. What is the equation for the reaction?

Answer. The equation for the reaction is as follows-

Mg + O 2 → MgO

Q12. Note down the observations for the experiment.

Answer. Some of the observations of the experiment are-

• Magnesium burns with dazzling white flame.
• A white powdery mass of magnesium oxide is formed.

Q13. What is the colour of the flame when magnesium burns in the air?

Answer. Magnesium burns with a dazzling white flame.

Q14. What will happen when the white powder is added to the water.

Answer. When white powder (magnesium oxide) is added to the water it forms Magnesium hydroxide [Mg(OH) 2 ].

Q15. Does Magnesium hydroxide have any effect on litmus paper?

Answer. Yes, on testing Magnesium hydroxide with litmus paper, it turns red litmus to blue.

Q16. Why does Magnesium hydroxide turn red litmus blue?

Answer. Magnesium hydroxide is basic in nature and therefore, it changes red litmus to blue. It has no effect on blue litmus paper.

Q17. Is magnesium oxide acidic or basic in nature?

Answer. Magnesium oxide is basic in nature.

Q18. What precautions should be taken while performing the experiment?

Answer. Some precautions that need to be taken while performing the experiment are as follows-

• Sand paper should be used to clean the magnesium ribbon.
• While burning, hold the magnesium ribbon with tongs.
• Do not look directly at the bright light associated with burning Mg. Wear sunglasses.
• It is not safe to handle white powder or magnesium oxide.

Q19. List the materials required for the experiment.

Answer. Magnesium Ribbon, burner, tongs, watch glass, pH paper strip/red litmus

Q20. Why is magnesium rubbed with sandpaper?

Answer. Magnesium is rubbed with sandpaper so as to remove any impurities present like rust, dust or greasy surface.

Q21. What type of reaction is the burning of magnesium ribbon?

Answer. The burning of magnesium ribbon is a combination reaction. This is because magnesium reacts with oxygen to form a single product magnesium oxide.

Q22. Is the reaction a chemical change or a physical change?

Answer. The reaction is a chemical change because a new product is formed.

Q23. What is the colour of magnesium metal?

Answer. The colour of magnesium metal is silvery white.

Q24. Will there be any change observed if the dry litmus paper is brought in contact with the ash of the magnesium ribbon?

Answer. No, there be no change observed if the dry litmus paper is brought in contact with the ash of the magnesium ribbon.

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