During an electrolysis , the cations are discharged at cathode .This is called reduction
Name two cations which will not be reduced in the presence of hydrogen ions .

Explanation

To solve the question, we need to identify two cations that will not be reduced at the cathode during electrolysis in the presence of hydrogen ions (H⁺). The key to answering this question lies in understanding the reactivity series of metals.

### Step-by-Step Solution:

1. **Understand Electrolysis and Reduction**: During electrolysis, cations (positively charged ions) are attracted to the cathode (negative electrode) where they gain electrons, a process known as reduction.

2. **Identify the Role of Hydrogen Ions**: In the presence of hydrogen ions (H⁺), we need to determine which cations are less likely to be reduced than hydrogen ions.

...