In the electrolysis refining of blister copper , a thin strip of pure copper is used as _______.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Process**: The electrolysis refining of blister copper involves the purification of copper. Blister copper is an impure form of copper that contains impurities such as sulfur.

2. **Identifying Electrodes**: In electrolysis, two electrodes are used: an anode (positive electrode) and a cathode (negative electrode). The anode is typically made of the impure substance, while the cathode is made of the pure substance.

3. **Role of the Cathode**: In the case of blister copper refining, a thin strip of pure copper is used as the cathode. This is where the reduction reaction occurs, and copper ions from the electrolyte are deposited as pure copper.

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