The equilibrium constant for the reaction
`H_2(g) + I_2(g) iff 2HI(g)`
at `440^@C` is 50. How many moles of hydrogen per mole of iodine are required to convert 90% of iodine into hydrogen iodide?

Explanation

To solve the problem, we need to determine how many moles of hydrogen (H₂) are required per mole of iodine (I₂) to convert 90% of iodine into hydrogen iodide (HI) under the given equilibrium constant (K).

### Step-by-Step Solution:

1. **Write the balanced chemical equation:**
\[ H_2(g) + I_2(g) \iff 2HI(g) \]
...