Question

Write a balanced equation for the production of synthesis gas, a mixture of \(\mathrm{H}_{2}\) and \(\mathrm{CO}\), from water and each of the following: (a) graphite (b) propane, \(\mathrm{C}_{3} \mathrm{H}_{8}(g)\)

Short answer

(a) Graphite: \(\mathrm{C(s) + H_2O(g) \rightarrow H_2(g) + CO(g)}\); (b) Propane: \(\mathrm{C_3H_8(g) + 3 H_2O(g) \rightarrow 3 CO(g) + 7 H_2(g)}\).

Step-by-step solution

Identify Reactants and Products

For the production of synthesis gas, the reactants are water (usually in the form of steam, \( \mathrm{H_2O} \)) and either graphite or propane. The products are hydrogen (\(\mathrm{H_2}\)) and carbon monoxide (\(\mathrm{CO}\)).

Write the Equation for Graphite

For graphite, the balanced chemical reaction is: \[\mathrm{C(s) + H_2O(g) \rightarrow H_2(g) + CO(g)}\] In this reaction, carbon (graphite) reacts with water to produce hydrogen and carbon monoxide. Both sides of the equation have the same number of each type of atom: 1 carbon, 2 hydrogen, and 1 oxygen.

Write the Equation for Propane

For propane, start by writing the unbalanced equation and then balance it: Unbalanced: \(\mathrm{C_3H_8(g) + H_2O(g) \rightarrow H_2(g) + CO(g)}\)Balanced: \(\mathrm{C_3H_8(g) + 3 H_2O(g) \rightarrow 3 CO(g) + 7 H_2(g)}\) Here, 3 propane molecules react with 3 water molecules to produce 3 carbon monoxide molecules and 7 hydrogen molecules. The equation is balanced with 3 carbon atoms, 8 hydrogen atoms, and 3 oxygen atoms on each side.

Verify Balanced Equations

Verify that both equations are balanced by counting atoms for each element on both sides: 1. Graphite: 1 C, 2 H, 1 O on both sides. 2. Propane: 3 C, 8 H, 3 O on both sides. This confirms that the equations are correctly balanced.

Key concepts

Balanced Chemical Equation

A balanced chemical equation ensures that the number of each type of atom is equal on both sides of the equation. This balance is crucial because it reflects the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. When writing a balanced equation, one must adjust the coefficients—not the subscripts of the formula—to balance the atoms.
For instance, in the production of synthesis gas using graphite, the equation is \[\mathrm{C(s) + H_2O(g) \rightarrow H_2(g) + CO(g)}\].

• The left side has 1 carbon, 2 hydrogen, and 1 oxygen atom.
• The right side also has 1 carbon, 2 hydrogen, and 1 oxygen atom.

This confirms that the equation is balanced. Keeping this balance is vital for calculating precise amounts of reactants and products.

Hydrogen Production

Hydrogen production from chemical reactions is essential for various industrial processes. In the context of synthesis gas, hydrogen is produced through the reaction of water with carbon-containing compounds.
When graphite reacts with steam in the equation, \[\mathrm{C(s) + H_2O(g) \rightarrow H_2(g) + CO(g)}\],

• Hydrogen atoms from the water are released as molecular hydrogen \(\mathrm{H_2}\).
• This method is an efficient way to obtain hydrogen, particularly in the chemical and energy industries.

Hydrogen is a crucial component in various applications, including fuel production and as a reactant in producing ammonia for fertilizers.

Carbon Monoxide Production

Carbon monoxide is another product formed during the synthesis gas production process. It results when water reacts with carbon-based substances like graphite or propane.
In the balanced equation with graphite, carbon monoxide is formed as \[\mathrm{C(s) + H_2O(g) \rightarrow H_2(g) + CO(g)}\]. Carbon monoxide is a colorless and odorless gas with significant industrial uses. It is utilized in metal refining, chemical synthesis, and as an intermediate in producing acetic acid and other chemicals. The ability to produce carbon monoxide efficiently through these reactions enhances its role in various manufacturing processes.

Chemical Reactions with Graphite

Graphite, a form of carbon, is a key reactant in producing synthesis gas. When graphite reacts with steam (water in the gaseous state), it forms hydrogen and carbon monoxide as given by the equation: \[\mathrm{C(s) + H_2O(g) \rightarrow H_2(g) + CO(g)}\].

• This process is known as the "water-gas" reaction.
• It is an endothermic reaction, meaning it absorbs heat.

Graphite is significant due to its stability and availability, making it a valuable resource in chemical industries for synthesis gas production. Its use underscores the importance of finding efficient ways to harness carbon resources.

Chemical Reactions with Propane

Propane, a hydrocarbon with the formula \(\mathrm{C_3H_8}\), reacts with water in the form of steam to produce synthesis gas. The balanced equation for this reaction is: \[\mathrm{C_3H_8(g) + 3 H_2O(g) \rightarrow 3 CO(g) + 7 H_2(g)}\].

• This reaction involves breaking down a larger carbon structure and reforming smaller molecules.
• It's important for its high yield of hydrogen, which is beneficial for energy applications.

Propane's reaction with water is more complex than graphite because of the need to balance more atoms, but it provides a valuable source of synthesis gas for various industrial uses.