Which one of the following pairs of substance will not produce hydrogen when reacted together?

Options

A. copper and conc. Nitric acid
B. Ethanol and metallic sodium
C. Magnesium and steam
D. Phenol and metallic sodium

Answer

D

Explanation

Copper being less reactive when reacts with conc. Nitric acid gives `NO_2` but not `H_2`
`Cu+4HNO_3 (conc) to Cu(NO_3)_2+2NO_2+2H_2O`
while mg and NaH being very reactive give hydrogen gas with steam and water respectively.
`Mg+2H_2O to MgO+H_2`
`NaH+H_2O to NaOH+H_2`
Ethanol and phenol due to the presence of acidic hydrogen also produce hydrogen with metallic sodium.
`C_2H_5OH+Nato C_2H_5O^2 Na^+ +H_2`
`C_6H_5OH+Na to C_6H_5O^(-) Na^+ +H_2`