The production of nascent hydrogen occurs when a metal reacts with an acid or an alkali and forms hydrogen gas. In an alkaline medium, nascent hydrogen is produced by the reaction of certain metals with hydroxide ions.
Among the given metal pairs:
1. Zn and Al: Both zinc (Zn) and aluminum (Al) can react with alkaline solutions to produce nascent hydrogen. Zinc reacts with alkalis to form hydrogen gas, and aluminum can react with alkali (especially when heated or in excess) to produce nascent hydrogen as well.
2. Fe and Ni: Both iron (Fe) and nickel (Ni) are less reactive in producing nascent hydrogen in alkaline media compared to the metals in other pairs.
3. Al and Mg: Magnesium (Mg) also reacts with alkalis to produce nascent hydrogen, but aluminum (Al) is more commonly known to produce nascent hydrogen when reacting with alkalis.
4. Mg and Zn: Magnesium reacts with alkaline solutions to form nascent hydrogen, but zinc is also quite reactive in alkaline solutions, although Al and Zn are more significant producers.
Answer: Zn and Al
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