Question

Which does not replace hydrogen from $HCl$ ?

• A. $Cu$
• B. $Mg$
• C. $Na$
• D. $Al$

Answer 1

Answer: (A)

$Cu$

Answer 2

Copper does not replace hydrogen from $HCl$ because in electrochemical series, it is present below hydrogen. $Al, Na$ and $Mg$ are present above hydrogen in electrochemical series, so they replace hydrogen.