When steam is passed over red hot iron, the substance formed are:

Options

A. `Fe_(2)O_(3)+H_(2)`
B. `Fe_(3)O_(4)+H_(2)`
C. `FeO+H_(2)`
D. `FeO+H_(2)+O_(2)`

Answer

To solve the question "When steam is passed over red hot iron, what substances are formed?", we can follow these steps:

### Step 1: Identify the Reactants
The reactants in this reaction are:
- Red hot iron (Fe)
- Steam (H2O)

### Step 2: Write the Chemical Reaction
When steam reacts with red hot iron, the reaction can be represented as:
\[ \text{Fe} + \text{H}_2\text{O} \rightarrow \text{Fe}_3\text{O}_4 + \text{H}_2 \]

### Step 3: Balance the Chemical Equation
To balance the equation, we need to ensure that the number of atoms of each element on the reactant side is equal to the number on the product side.

1. Start with iron (Fe):
- On the product side, we have 3 Fe in Fe3O4, so we need 3 Fe on the reactant side.

2. Next, balance the oxygen (O):
- In Fe3O4, there are 4 oxygen atoms. Since each water molecule (H2O) has 1 oxygen, we need 4 H2O to provide 4 oxygen atoms.

3. Finally, balance the hydrogen (H):
- From 4 H2O, we have 8 hydrogen atoms. Therefore, we need to ensure that we have 8 hydrogen atoms on the product side. This means we will produce 4 H2 gas molecules.

Putting this all together, the balanced equation is:
\[ 3 \text{Fe} + 4 \text{H}_2\text{O} \rightarrow \text{Fe}_3\text{O}_4 + 4 \text{H}_2 \]

### Step 4: Identify the Products
From the balanced equation, we can see that the products formed when steam is passed over red hot iron are:
- Iron(II,III) oxide (Fe3O4)
- Hydrogen gas (H2)

### Final Answer
Therefore, when steam is passed over red hot iron, the substances formed are Fe3O4 and H2.

---