Question

Observe the given diagram and fill in the blanks by choosing the correct option.

	$X$	$Y$	$Z$
(a)	$H_{2(g)}$ at $1atm$	$10^{-2}M{H}^{+}$	Finely divided $Pt$
(b)	$H_{2(g)}$ at $1bar$	$1.00M{H}^{+}$	Finely divided $Pt$
(c)	$1.00M{H}^{+}$	$H_{2(g)}$ at $1bar$	Finely divided $Ni$
(d)	$H_{2(g)}$ at $1bar$	$1.00M{H}^{+}$	$Pt$ granules

• A. a
• B. b
• C. c
• D. d

Answer 1

Answer: (B)

This is standard hydrogen electrode.
It contain platinum wire,
From $x,H_2(g)$ is passed at $1bar$.
where as, $y$ is $1M$ concentration of $H^{+}$(acid)
$Z$ is finely divided platinum coated platinum on platinum foil.
Overall reaction- $H^{+}(aq)+2e^{-}⟶H_2(g)$