In which of the following chemical equations, the abbreviations represent the correct states of the reactants and products involved at reaction temperature?

Options

A. `2H_(2)(l)+O_(2)(l)to2H_(2)O(g)`
B. `2H_(2)(g)+O_(2)(l)to2H_(2)O(l)`
C. `2H_(2)(g)+O_(2)(g)to2H_(2)O(l)`
D. `2H_(2)(g)+O_(2)(g)to2H_(2)O(g)`

Explanation

To determine which chemical equation correctly represents the states of the reactants and products at reaction temperature, we need to analyze the states of matter for each substance involved in the reaction.

### Step-by-Step Solution:

1. **Identify the Reactants and Products**:
- In the formation of water, the reactants are hydrogen (H₂) and oxygen (O₂), and the product is water (H₂O).

2. **Determine the State of Each Substance**:
- **Hydrogen (H₂)**: At standard conditions (0°C and 1 atm), hydrogen exists as a gas (g).
- **Oxygen (O₂)**: Similarly, oxygen also exists as a gas (g) under standard conditions.
- **Water (H₂O)**: At standard conditions, water is typically found in a liquid state (l).

3. **Write the Chemical Equation with States**:
- The balanced chemical equation for the formation of water can be written as:
\[ 2H_2(g) + O_2(g) \rightarrow 2H_2O(l) \]
- Here, (g) indicates gas and (l) indicates liquid.

4. **Analyze the Options Provided**:
- Review each option given in the question to see which one matches the states identified above.
- The correct option should indicate that H₂ is a gas, O₂ is a gas, and H₂O is a liquid.

5. **Select the Correct Option**:
- Based on the analysis, the correct option is the one that states:
- H₂ is a gas (g)
- O₂ is a gas (g)
- H₂O is a liquid (l)
- This corresponds to option number three.

### Final Answer:
The correct answer is option number three, which states that H₂ is a gas, O₂ is a gas, and H₂O is a liquid at reaction temperature.