Question

Which is the balanced equation for V2O5 + CaS → CaO + V2S5?

V2O5 + CaS → CaO + V2S5
5V2O5 + 5CaS → 10CaO + 5V2S5
3V2O5 + 3CaS → 3CaO + 3V2S5
V2O5 + 5CaS → 5CaO + V2S5

Answer 1

To determine the balanced equation for the reaction \( \text{V}_2\text{O}_5 + \text{CaS} \rightarrow \text{CaO} + \text{V}_2\text{S}_5 \), we need to ensure that the number of atoms of each element is the same on both sides of the equation.

Let's break it down:

1. On the left side:
- V: 2 (from \( \text{V}_2\text{O}_5 \))
- O: 5 (from \( \text{V}_2\text{O}_5 \))
- Ca: 1 (from \( \text{CaS} \))
- S: 1 (from \( \text{CaS} \))

2. On the right side:
- V: 2 (from \( \text{V}_2\text{S}_5 \))
- O: 1 (from \( \text{CaO} \))
- Ca: 1 (from \( \text{CaO} \))
- S: 5 (from \( \text{V}_2\text{S}_5 \))

To balance it, we start with the vanadium (V) and sulfur (S) species. The products show that 5 sulfur atoms are produced, so we need to have enough \( \text{CaS} \) to provide this sulfur.

If we try the last option provided:

\( \text{V}_2\text{O}_5 + 5 \text{CaS} \rightarrow 5 \text{CaO} + \text{V}_2\text{S}_5 \)

Check this:

**Left Side:**
- V: 2
- O: 5
- Ca: 5
- S: 5

**Right Side:**
- V: 2
- O: 5
- Ca: 5
- S: 5

Both sides are balanced.

Thus, the correct balanced equation is:

\[
\text{V}_2\text{O}_5 + 5 \text{CaS} \rightarrow 5 \text{CaO} + \text{V}_2\text{S}_5
\]

So the answer is:

**V2O5 + 5CaS → 5CaO + V2S5.**