Problem 71 - Chemistry Matter and Change

Question

Write skeleton equations for these reactions. a. iron(s) \(+\) fluorine(g) \(\rightarrow\) iron (III) fluoride \((s)\) b. sulfur trioxide(g) \(+\) water \((1) \rightarrow\) sulfuric acid(aq) c. sodium(s) + magnesium iodide(aq) \(\rightarrow\) sodium iodide(aq) + magnesium(s) d. vanadium(s) \(+\) oxygen \((\mathrm{g}) \rightarrow\) vanadium \((\mathrm{V})\) oxide(s)

Step-by-Step Solution

Answer

The short answer for the skeleton equations of the given reactions is: a) \(Fe(s) + F_{2}(g) \rightarrow FeF_{3}(s)\) b) \(SO_{3}(g) + H_{2}O(l) \rightarrow H_{2}SO_{4}(aq)\) c) \(Na(s) + MgI_{2}(aq) \rightarrow NaI(aq) + Mg(s)\) d) \(V(s) + O_{2}(g) \rightarrow V_{2}O_{5}(s)\)

Step 1: Reaction 1: Iron(s) + Fluorine(g) -> Iron (III) Fluoride(s)

Here, Iron (Fe) reacts with Fluorine (F2) to form Iron (III) Fluoride (FeF3). So, the skeleton equation for the first reaction is: \(Fe(s) + F_{2}(g) \rightarrow FeF_{3}(s)\)

Step 2: Reaction 2: Sulfur Trioxide(g) + Water(l) -> Sulfuric Acid(aq)

In this reaction, Sulfur Trioxide (SO3) reacts with Water (H2O) to form Sulfuric Acid (H2SO4). The skeleton equation for this reaction is: \(SO_{3}(g) + H_{2}O(l) \rightarrow H_{2}SO_{4}(aq)\)

Step 3: Reaction 3: Sodium(s) + Magnesium Iodide(aq) -> Sodium Iodide(aq) + Magnesium(s)

This is a single-displacement reaction, where Sodium (Na) takes the place of Magnesium (Mg) in Magnesium Iodide (MgI2) to form Sodium Iodide (NaI) and Magnesium. The skeleton equation is: \(Na(s) + MgI_{2}(aq) \rightarrow NaI(aq) + Mg(s)\)

Step 4: Reaction 4: Vanadium(s) + Oxygen(g) -> Vanadium(V) Oxide(s)

Here, Vanadium (V) reacts with Oxygen (O2) to form Vanadium(V) Oxide (V2O5). The skeleton equation for this reaction is: \(V(s) + O_{2}(g) \rightarrow V_{2}O_{5}(s)\)

Key Concepts

Skeleton Equations

A skeleton equation is the first step in writing a complete chemical equation. It shows the reactants and products of a chemical reaction using their chemical formulas, but without indicating the quantities of each substance involved. This lack of quantity detail means that skeleton equations need to be balanced later. However, they are crucial because they provide the basic framework for understanding which substances are reacting. For example, if we consider iron reacting with fluorine to form iron(III) fluoride, the skeleton equation would look like this: \[Fe(s) + F_{2}(g) \rightarrow FeF_{3}(s)\]This is a simple representation of the reaction which needs further balancing to adhere to the conservation of mass. Skeleton equations are useful for identifying the basic form of a chemical reaction before delving into more complex calculations.

Reaction Types

Chemical reactions can be classified into several types based on how the reactants turn into products. These categories help in predicting product formation and understanding the reaction's mechanics. Common types include:

• Combination reactions, where two or more substances combine to form a single product.
• Decomposition reactions, which involve a single compound breaking down into two or more simpler substances.
• Single-displacement reactions, where one element displaces another in a compound.
• Double-displacement reactions, where parts of two compounds are exchanged to form two new compounds.
• Combustion reactions, which involve a substance combining with oxygen, releasing energy.

Each reaction type has its characteristics and follows specific patterns, which are beneficial for predicting reaction courses and products.

Chemical Reactions

Chemical reactions involve the transformation of substances through the breaking and forming of chemical bonds. During a chemical reaction, the atoms in the reactants rearrange to form new products. This rearrangement is what leads to the different physical or chemical properties observed in the products. Reactions occur under varying conditions and may involve:

• Changes in temperature or pressure.
• The presence of catalysts that speed up the reaction without being consumed.
• The absorption or release of energy, which can often be measured as temperature change.

Understanding the nature of chemical reactions is crucial for fields ranging from material sciences to biochemistry. Knowing how substances interact, transform, and the conditions that influence these reactions is vital for harnessing their potential in practical applications.

Single-Displacement Reactions

Single-displacement reactions, also known as single-replacement reactions, involve an element displacing another in a compound, resulting in the formation of a new element and a new compound. An example is when sodium replaces magnesium in magnesium iodide, which can be represented by the equation:\[Na(s) + MgI_{2}(aq) \rightarrow NaI(aq) + Mg(s)\]Here, sodium (a more reactive metal) substitutes magnesium in magnesium iodide to form sodium iodide and elemental magnesium. These reactions are common in electrochemistry and are often forecasted using reactivity series or electrochemical series, which rank elements based on their ability to displace others from compounds. Single-displacement reactions are fundamental in metallurgy for extracting metals and manufacturing essential chemicals.