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A chemical reaction involves transforming reactants into products. This change often involves breaking and forming chemical bonds. In our exercise, carbon (C) reacts with sulfur dioxide (SOâ‚‚) to form carbon disulfide (CSâ‚‚) and carbon monoxide (CO). The reaction can be represented as:

\[ 5 \text{C}(s) + 2 \text{SO}_2(g) \rightarrow \text{CS}_2(l) + 4 \text{CO}(g) \]

Reactants are substances that undergo a chemical change, and products are the new substances formed as a result of the reaction. In the example above:

• Reactants: Carbon (C) and Sulfur Dioxide (SOâ‚‚)
• Products: Carbon Disulfide (CSâ‚‚) and Carbon Monoxide (CO)

Understanding how substances interact in a reaction helps us predict and quantify the changes that occur. This is a foundational concept in stoichiometry.

The mole ratio is a key part of stoichiometry. It comes from the coefficients of a balanced chemical equation. In our example, the balanced equation is:

\[ 5 \text{C}(s) + 2 \text{SO}_2(g) \rightarrow \text{CS}_2(l) + 4 \text{CO}(g) \]

The coefficients tell us the ratio in which reactants combine and products form. Here are the key mole ratios from the equation:

• 5 moles of C react with 2 moles of SOâ‚‚
• 2 moles of SOâ‚‚ produce 1 mole of CSâ‚‚
• 5 moles of C produce 4 moles of CO

These ratios are used to find how many moles of one substance are needed or produced, given the amount of another substance. For example: To find the moles of C required for 0.500 moles of SOâ‚‚, we use the mole ratio \[ \frac{5 \text{ moles C}}{2 \text{ moles SO}_2} \] and multiply it by 0.500 moles SOâ‚‚:

\[ \frac{5 \text{ moles C}}{2 \text{ moles SO}_2} \times 0.500 \text{ moles SO}_2 = 1.25 \text{ moles C} \]
Understanding mole ratios allows us to interconvert between the amounts of reactants and products.

A balanced chemical equation ensures the conservation of mass, showing that atoms are neither created nor destroyed in a chemical reaction. This means the number of each type of atom on the reactant side equals the number on the product side.

\[ 5 \text{C}(s) + 2 \text{SO}_2(g) \rightarrow \text{CS}_2(l) + 4 \text{CO}(g) \]

Let's check the balance:

• Carbon (C): 5 atoms on the reactant side and (1 CSâ‚‚ + 4 CO) = 5 atoms on the product side
• Sulfur (S): 2 atoms on the reactant side and 1 atom in CSâ‚‚ product
• Oxygen (O): 4 atoms on the reactant side and (2 COâ‚‚ + 4 CO) = 6 atoms on the product side

Balancing requires adjusting the coefficients so that both sides have the same number of each type of atom. Here, it's balanced as: 5 moles of C with 2 moles of SOâ‚‚ give 1 mole of CSâ‚‚ and 4 moles of CO. Balancing is crucial for accurate calculations in stoichiometry. Accurate balanced equations enable us to correctly interrelate the moles of reactants and products in any chemical reaction.