# gpqa-diamond / 82

- taskset: [gpqa-diamond](https://harnessreport.com/tasks/gpqa-diamond.md)
- difficulty: difficult
- category: reasoning
- language: 
- runnable from the site: no
- agent timeout: 3600s

## Results by harness

_none yet_

## Instruction

```
What is the correct answer to this question: 
We dilute 20.00 cm3 0.05 M acetic acid with 20.00 cm3 water, then titrate the resulting solution with 0.1M NaOH (25 °C). What will be the value of pH at 25% titration and at the equivalence point? The Ka of acetic acid is 1.85x10^-5.

Choices:
  (A) 3.17; 6.73  
  (B) 4.26; 8.52
  (C) 4.73; 7.00
  (D) 4.57; 6.92  

Let's think step by step:

[First, reason through the problem carefully. Consider all relevant concepts, formulas, and principles. Break down complex problems into manageable steps. Evaluate each answer choice critically.]

Based on your reasoning above, determine the single, most likely answer choice. Then write ONLY the letter of your final answer (A, B, C, or D) to `/app/answer.txt`.

**Important:**
- This is a challenging graduate-level question in biology, physics, or chemistry
- Do not try to solve the question in a single step. Break it down into smaller steps.
- You should ONLY interact with the environment provided to you AND NEVER ASK FOR HUMAN HELP.
- The answer file must contain only a single uppercase letter (A, B, C, or D) with no additional text or explanation
- You can show your work and reasoning before writing the final answer, but the file `/app/answer.txt` should contain only the letter
```
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