Which of the following metals is least reactive with acids? 

The correct answer is Copper.

Key Points

• Copper is one of the least reactive metals with acids, making it less likely to corrode or tarnish when exposed to acidic environments.
• In the reactivity series of metals, copper is placed below hydrogen, indicating its lower reactivity with acids.
• When copper reacts with acids, it does not produce hydrogen gas, unlike more reactive metals such as zinc or iron.
• Due to its low reactivity, copper is often used in plumbing, roofing, and electrical wiring where resistance to corrosion is essential.

Additional Information

• Reactivity Series:
  • The reactivity series is a list of metals arranged in order of decreasing reactivity.
  • Metals higher in the series react more vigorously with acids and other substances.
  • Metals like potassium and sodium are highly reactive, while gold and platinum are the least reactive.
• Hydrogen Production:
  • Reactive metals such as zinc and iron react with acids to produce hydrogen gas.
  • Copper, being less reactive, does not produce hydrogen gas when it reacts with acids.
• Corrosion Resistance:
  • Copper's resistance to corrosion is due to its low reactivity with environmental substances, including acids.
  • This property makes copper suitable for use in various applications where long-term durability is required.
• Uses of Copper:
  • Copper is extensively used in electrical wiring due to its excellent conductivity and resistance to corrosion.
  • It is also used in plumbing, roofing, and industrial machinery.