Skip to main content
Ch.3 - Mass Relationships in Chemical Reactions
Chapter 3, Problem 64a

Magnesium metal burns in oxygen to form magnesium oxide, MgO. (a) Write a balanced equation for the reaction.

Verified step by step guidance
1
Identify the reactants and products: Magnesium (Mg) and oxygen (O₂) are the reactants, and magnesium oxide (MgO) is the product.
Write the unbalanced chemical equation: Mg + O₂ → MgO.
Balance the equation by adjusting coefficients: Start by balancing the number of oxygen atoms. Since O₂ has 2 oxygen atoms, you need 2 MgO to balance the oxygen atoms, resulting in Mg + O₂ → 2 MgO.
Balance the magnesium atoms: Since there are 2 MgO molecules, you need 2 Mg atoms on the reactant side, resulting in 2 Mg + O₂ → 2 MgO.
Verify the balance: Ensure that there are equal numbers of each type of atom on both sides of the equation. There are 2 Mg atoms and 2 O atoms on each side, confirming the equation is balanced.

Verified Solution

Video duration:
4m
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Balancing Chemical Equations

Balancing chemical equations is essential to ensure that the law of conservation of mass is upheld, meaning the number of atoms of each element must be the same on both sides of the equation. This involves adjusting coefficients in front of the chemical formulas to achieve balance, reflecting the actual stoichiometry of the reaction.
Recommended video:
Guided course
01:32
Balancing Chemical Equations

Combustion Reactions

Combustion reactions involve a substance (usually a hydrocarbon or metal) reacting with oxygen to produce heat and light, often resulting in the formation of oxides. In the case of magnesium, it reacts with oxygen to form magnesium oxide, illustrating a typical combustion reaction where a metal burns in the presence of oxygen.
Recommended video:
Guided course
02:24
Combustion Apparatus

Stoichiometry

Stoichiometry is the quantitative relationship between reactants and products in a chemical reaction. It allows chemists to predict the amounts of substances consumed and produced in a reaction, which is crucial for writing balanced equations and understanding the proportions in which elements combine.
Recommended video:
Guided course
01:16
Stoichiometry Concept
Related Practice
Textbook Question
Iron metal can be produced from the mineral hematite, Fe2O3, by reaction with carbon. How many kilograms of iron are present in 105 kg of hematite?
800
views
Textbook Question
In the preparation of iron from hematite, Fe2O3 reacts with carbon: Fe2O3 + C --> Fe + CO2 Unbalanced (a) Balance the equation. (b) How many moles of carbon are needed to react with 525 g of hematite? (c) How many grams of carbon are needed to react with 525 g of hematite?
1589
views
Open Question
An alternative method for preparing pure iron from Fe2O3 is by reaction with carbon monoxide: Fe2O3 + CO --> Fe + CO2 Unbalanced. (a) Balance the equation. (b) How many grams of CO are needed to react with 3.02 g of Fe2O3? (c) How many grams of CO are needed to react with 1.68 mol of Fe2O3?
Textbook Question

Magnesium metal burns in oxygen to form magnesium oxide, MgO. (b) How many grams of oxygen are needed to react with 25.0 g of Mg? How many grams of MgO will result?

1698
views
Textbook Question

Magnesium metal burns in oxygen to form magnesium oxide, MgO. (c) How many grams of Mg are needed to react with 25.0 g of O2? How many grams of MgO will result?

782
views
Textbook Question
Ethylene gas, C2H4, reacts with water at high temperature to yield ethyl alcohol, C2H6O. (a) How many grams of ethylene are needed to react with 0.133 mol of H2O? How many grams of ethyl alcohol will result? (b) How many grams of water are needed to react with 0.371 mol of ethylene? How many grams of ethyl alcohol will result?
2674
views