`K_(2)Cr_(2)O_(7)+NaoH to CrO_(4)^(2-)`

Options

A. For coloured ppt./Black ppt
B. For coloured solution.
C. for clear/colourless solution
D. For white ppt.

Answer

To solve the question regarding the reaction between potassium dichromate (K₂Cr₂O₇) and sodium hydroxide (NaOH) to form chromate ions (CrO₄²⁻), we will analyze the reaction step by step.

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactants are potassium dichromate (K₂Cr₂O₇) and sodium hydroxide (NaOH).

2. **Understand the Reaction**:
- Potassium dichromate is a strong oxidizing agent and in the presence of a strong base like NaOH, it can convert into chromate ions (CrO₄²⁻).

3. **Write the Reaction**:
- The balanced chemical equation can be represented as:
\[ K_2Cr_2O_7 + 2NaOH \rightarrow 2Na_2CrO_4 + H_2O \]
- Here, K₂Cr₂O₇ reacts with NaOH to produce sodium chromate (Na₂CrO₄) and water.

4. **Determine the Color of the Products**:
- The chromate ion (CrO₄²⁻) is known to be yellow in color. Therefore, the solution formed will be colored.

5. **Conclusion**:
- Since CrO₄²⁻ is a colored ion, the resulting solution will be a colored solution rather than a colorless solution or precipitate.

### Final Answer:
The reaction between K₂Cr₂O₇ and NaOH will form a colored solution due to the presence of CrO₄²⁻ ions.

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