To answer the question correctly, let's consider the details of the chemical reaction between hydrogen gas and oxygen gas in the presence of a platinum catalyst.
We know that hydrogen gas ([tex]\(H_2\)[/tex]) reacts with oxygen gas ([tex]\(O_2\)[/tex]) to form water ([tex]\(H_2O\)[/tex]). This reaction can be facilitated by a platinum catalyst but the catalyst is not consumed in the reaction itself; it only speeds up the reaction.
### Balancing the Chemical Equation:
The products of the reaction should be water in gaseous form ([tex]\(H_2O(g)\)[/tex]).
1. Write the unbalanced chemical equation for the reaction:
[tex]\[
H_2(g) + O_2(g) \rightarrow H_2O(g)
\][/tex]
2. Balance the number of hydrogen atoms:
- On the left side, we have 2 hydrogen atoms in [tex]\(H_2(g)\)[/tex].
- On the right side, we need 2 hydrogen atoms in [tex]\(H_2O(g)\)[/tex], so we place a coefficient of 2 in front of [tex]\(H_2O\)[/tex]:
[tex]\[
H_2(g) + O_2(g) \rightarrow 2 H_2O(g)
\][/tex]
3. Balance the number of oxygen atoms:
- On the left side, we have 2 oxygen atoms in [tex]\(O_2(g)\)[/tex].
- On the right side, we already have 2 oxygen atoms (since [tex]\(2 H_2O\)[/tex] contains 4 hydrogen atoms and 2 oxygen atoms: [tex]\(2 \times H_2O\)[/tex]).
Thus, the balanced chemical equation is:
[tex]\[
2 H_2(g) + O_2(g) \rightarrow 2 H_2O(g)
\][/tex]
4. Include the catalyst:
The reaction occurs in the presence of platinum ([tex]\(Pt\)[/tex]), but the catalyst does not appear among the products. It is written above the arrow indicating its role in facilitating the reaction.
Therefore, the correctly balanced equation with the catalyst involved is:
[tex]\[
2 H_2(g) + O_2(g) \xrightarrow{Pt} 2 H_2O(g)
\][/tex]
### Analyzing the Provided Options:
Let's examine the specific options given in the question:
1. [tex]\(
H_2(g) + O_2(g) + Pt \rightarrow H_2(g) + O_2(g)
\)[/tex]
- This option suggests that the reactants do not change, which is incorrect.
2. [tex]\(
H_2(g) + O_2(g) \rightarrow H_2(g) + O_2(g) + Pt
\)[/tex]
- This option suggests that the reactants do not change and incorrectly includes [tex]\(Pt\)[/tex] among the products, which is incorrect.
3. [tex]\(
2 H_2(g) + O_2(g) \xrightarrow{Pt} 2 H_2O(g) + Pt
\)[/tex]
- This option correctly balances the reactants and products but incorrectly includes [tex]\(Pt\)[/tex] among the products. Therefore, this is also incorrect.
4. [tex]\(
2 H_2(g) + O_2(g) \xrightarrow{Pt} 2 H_2O(g)
\)[/tex]
- This represents the balanced equation with the catalyst shown correctly above the arrow and not included as a product.
### Conclusion:
The correct equation representing this reaction is:
[tex]\[
2 H_2(g) + O_2(g) \xrightarrow{Pt} 2 H_2O(g)
\][/tex]
Thus, the correct option is the fourth one:
[tex]\[
2 H_2(g) + O_2(g) \xrightarrow{Pt} 2 H_2O(g)
\][/tex]
