Question

(a) Write an equation to show how Mg reacts with \(\mathrm{N}_{2}\) when heated. (b) Suggest how the product reacts with water.

Short answer

(a) \( 3\mathrm{Mg} + \mathrm{N}_2 \rightarrow \mathrm{Mg}_3 \mathrm{N}_2 \). (b) \( \mathrm{Mg}_3 \mathrm{N}_2 + 6\mathrm{H}_2\mathrm{O} \rightarrow 3\mathrm{Mg(OH)}_2 + 2\mathrm{NH}_3 \).

Step-by-step solution

Understanding the Reactants

First, identify the reactants in the reaction. The reactants in this equation are magnesium (Mg) and nitrogen gas \( \mathrm{N}_2 \). When heated, magnesium reacts with nitrogen.

Balanced Equation for Mg and N2

Write the chemical equation showing the reaction of Mg with \( \mathrm{N}_2 \) to form magnesium nitride \( \mathrm{Mg}_3 \mathrm{N}_2 \). The balanced chemical equation is: \[3\mathrm{Mg} + \mathrm{N}_2 \rightarrow \mathrm{Mg}_3 \mathrm{N}_2\]

Identifying Product Reaction with Water

The product, magnesium nitride \( \mathrm{Mg}_3 \mathrm{N}_2 \), will react with water \( \mathrm{H}_2\mathrm{O} \) in the following way: \( \mathrm{Mg}_3 \mathrm{N}_2 \) reacts with water to produce magnesium hydroxide \( \mathrm{Mg(OH)}_2 \) and ammonia \( \mathrm{NH}_3 \).

Balanced Equation for Reaction with Water

Write and balance the chemical equation for the reaction of \( \mathrm{Mg}_3 \mathrm{N}_2 \) with \( \mathrm{H}_2\mathrm{O} \). The balanced equation is: \[\mathrm{Mg}_3 \mathrm{N}_2 + 6\mathrm{H}_2\mathrm{O} \rightarrow 3\mathrm{Mg(OH)}_2 + 2\mathrm{NH}_3\]

Key concepts

Understanding Magnesium Nitride

Magnesium nitride is an intriguing compound that forms when magnesium (Mg) reacts with nitrogen gas (\( \mathrm{N}_2 \)). This reaction typically occurs when the two elements are heated together. Magnesium, a metal in group 2 of the periodic table, is quite reactive, especially at elevated temperatures. When it combines with nitrogen, a gaseous non-metal, they form magnesium nitride, symbolized as \( \mathrm{Mg}_3 \mathrm{N}_2 \).

The reaction to form magnesium nitride is a type of synthesis reaction, where multiple reactants combine to form a single product. The chemical equation for this reaction is:\[3\mathrm{Mg} + \mathrm{N}_2 \rightarrow \mathrm{Mg}_3 \mathrm{N}_2\]

• The equation shows that three magnesium atoms react with one nitrogen molecule.
• This must be balanced with respect to both reactants and the product.
• It indicates a stoichiometric relationship where magnesium and nitrogen combine in a 3:1 ratio to form magnesium nitride.

Understanding magnesium nitride's formation and properties is crucial because its reactivity plays a role in various chemical processes and potential industrial applications.

Crafting Chemical Equations

Chemical equations are a way of representing chemical reactions using symbols for the elements and compounds involved. Crafting a chemical equation requires a clear understanding of the reactants and products involved in the reaction. Let's break it down with the example given:

When magnesium reacts with nitrogen, the equation is:\[3\mathrm{Mg} + \mathrm{N}_2 \rightarrow \mathrm{Mg}_3 \mathrm{N}_2\]This equation represents the synthesis of magnesium nitride. Here's how to approach such equations:

• Start by writing down the symbols for each reactant and product.
• Ensure the equation is balanced—meaning the same number of each type of atom appears on both sides of the arrow.
• Balance the equation by adjusting coefficients, which are the numbers placed in front of the chemical formulas.

Balancing chemical equations ensures that the law of conservation of mass is followed, which states that matter cannot be created or destroyed. For magnesium nitride, this balancing is crucial for predicting how much of each substance is involved in or produced by the reaction.

Exploring the Reaction with Water

Magnesium nitride, once formed, has the interesting property of reacting with water. This is a decomposition reaction where magnesium nitride reacts with water to form new products. The balanced chemical equation for this interaction is:\[\mathrm{Mg}_3 \mathrm{N}_2 + 6\mathrm{H}_2\mathrm{O} \rightarrow 3\mathrm{Mg(OH)}_2 + 2\mathrm{NH}_3\]Here’s what happens in this reaction:

• Magnesium nitride breaks down when it reacts with water.
• It forms magnesium hydroxide \( \mathrm{Mg(OH)}_2 \), a white, solid compound.
• Ammonia \( \mathrm{NH}_3 \), a gas with a sharp smell, is also produced.

This reaction demonstrates the reactivity of magnesium nitride. Understanding reactions like this is important for learning how different chemicals interact, which can be applied in fields ranging from industrial processes to environmental science. The conversion of solid magnesium nitride into hydroxy compound and ammonia gas is a practical example of how chemistry can transform substances.