Questions: INTERACTIVE EXAMPLE Determining Mole Ratios Consider the following unbalanced equation: NH3(g) → N2(g) + H2(g) How many moles of N2 will be produced by the decomposition of 2.61 moles of ammonia What is the balanced equation for this reaction (in lowest multiple integers)? NH3(g) → N2(g) + H2(g)

INTERACTIVE EXAMPLE Determining Mole Ratios
Consider the following unbalanced equation:
NH3(g) → N2(g) + H2(g)

How many moles of N2 will be produced by the decomposition of 2.61 moles of ammonia
What is the balanced equation for this reaction (in lowest multiple integers)?
NH3(g) → N2(g) + H2(g)

Transcript text: INTERACTIVE EXAMPLE Determining Mole Ratios Consider the following unbalanced equation: \[ \mathrm{NH}_{3}(\mathrm{~g}) \rightarrow \mathrm{N}_{2}(\mathrm{~g})+\mathrm{H}_{2}(\mathrm{~g}) \] How many moles of $\mathrm{N}_{2}$ will be produced by the decomposition of 2.61 moles of ammonia What is the balanced equation for this reaction (in lowest multiple integers)? $\square$ I $\mathrm{NH}_{3}(\mathrm{~g}) \rightarrow$ $\square$ $\mathrm{N}_{2}(g)+$ $\square$ $\mathrm{H}_{2}(g)$

Solution

Solution Steps

Step 1: Balance the Chemical Equation

To determine the mole ratios, we first need to balance the chemical equation. The unbalanced equation is:

\[ \mathrm{NH}_{3}(\mathrm{~g}) \rightarrow \mathrm{N}_{2}(\mathrm{~g}) + \mathrm{H}_{2}(\mathrm{~g}) \]

Balancing the equation involves ensuring that the number of each type of atom is the same on both sides of the equation.

Nitrogen (N): There are 2 nitrogen atoms in $\mathrm{N}_{2}$, so we need 2 $\mathrm{NH}_{3}$ molecules to provide 2 nitrogen atoms.
Hydrogen (H): Each $\mathrm{NH}_{3}$ has 3 hydrogen atoms, so 2 $\mathrm{NH}_{3}$ molecules have 6 hydrogen atoms. Therefore, we need 3 $\mathrm{H}_{2}$ molecules to balance the hydrogen atoms.

The balanced equation is:

\[ 2 \mathrm{NH}_{3}(\mathrm{~g}) \rightarrow \mathrm{N}_{2}(\mathrm{~g}) + 3 \mathrm{H}_{2}(\mathrm{~g}) \]

Step 2: Determine the Mole Ratio

From the balanced equation, the mole ratio of $\mathrm{NH}_{3}$ to $\mathrm{N}_{2}$ is 2:1. This means that 2 moles of $\mathrm{NH}_{3}$ produce 1 mole of $\mathrm{N}_{2}$.

Step 3: Calculate Moles of $\mathrm{N}_{2}$ Produced

Given that 2.61 moles of $\mathrm{NH}_{3}$ decompose, we use the mole ratio to find the moles of $\mathrm{N}_{2}$ produced:

\[ \text{Moles of } \mathrm{N}_{2} = \frac{1 \text{ mole of } \mathrm{N}_{2}}{2 \text{ moles of } \mathrm{NH}_{3}} \times 2.61 \text{ moles of } \mathrm{NH}_{3} = 1.305 \text{ moles of } \mathrm{N}_{2} \]