Question

2c₂h₂(g) + 5o₂(g) → 4co₂(g) + 2h₂o(g)
how many liters of c₂h₂ are required to produce 8 l of co₂, assuming the reaction is at stp?
the ratios are: 2 l c₂h₂/4 l co₂ or 4 l co₂/2 l c₂h₂
? l c₂h₂

Explanation:

Step1: Identify volume ratio

From the balanced equation, the volume ratio of $\text{C}_2\text{H}_2$ to $\text{CO}_2$ is $\frac{2\ \text{L}\ \text{C}_2\text{H}_2}{4\ \text{L}\ \text{CO}_2} = \frac{1}{2}$.

Step2: Calculate required $\text{C}_2\text{H}_2$

Multiply the target $\text{CO}_2$ volume by the ratio: $8\ \text{L}\ \text{CO}_2 \times \frac{2\ \text{L}\ \text{C}_2\text{H}_2}{4\ \text{L}\ \text{CO}_2} = 4\ \text{L}$.

Answer:

4 L