JEE Main · 2021 · 25 Jul 2021 · Shift 2 · Equilibrium

WhatsApp Email

Assuming that Ba(OH)₂ is completely ionized in aqueous solution under the given conditions, the concentration of H₃O⁺ ions in 0.005 M aqueous solution of Ba(OH)₂ at 298 K is ______ × 10⁻¹² mol L⁻¹. (nearest integer)

Answer: 1

Solution

Complete ionisation of

Ba (OH)_{2}

releases two hydroxide ions per formula unit, so

[O H^{-}] = 2 \times 0.005 = 0.01

mol L

^{- 1}

. At 298 K the ionic product of water fixes the hydronium ion concentration:

[H_{3} O^{+}] = \frac{K _{w}}{[ O H ^{-} ]} = \frac{1.0 \times 1 0 ^{- 14}}{1.0 \times 1 0 ^{- 2}} = 1.0 \times 1 0^{- 12} mol L^{- 1}

The hydronium ion concentration is

1 \times 1 0^{- 12}

mol L

^{- 1}

JEE Main · 2021 · 25 Jul 2021 · Shift 2 · Integer answer

Practise more: all JEE Main PYQs on Equilibrium →

More JEE Main questions on Equilibrium

The first and second ionization constants of $H_{2} X$ are $2.5 \times 1 0^{- 8}$ and $1.0 \times 1 0^{- 13}$ respectively. The concentration of $X^{2 -}$ in $0.1 M$ $H_{2} X$ solution is $____$ $\times 1 0^{- 15} M$ . (N …
JEE Main 2026View solution →
Which of the following mixture gives a buffer solution with $pH = 9.25$ ?
Given : $pK_{b} (NH_{4} OH) = 4.75$
JEE Main 2026View solution →
Consider the general reaction given below at 400 K
$x A (g) y B (g)$

The values of $K_{p}$ and $K_{c}$ are studied under the same condition of temperature but variation in x and y.
(i) $K_{p} = 85.87$ and $K_{c} = 2.586$ appropriate units
(ii) $K_{p} = 0.862$ and …
JEE Main 2026View solution →
For the following gas phase equilibrium reaction at constant temperature,
$NH X_{3} (g) \frac{1}{2} N X_{2} (g) + \frac{3}{2} H X_{2} (g)$

If the total pressure is $3$ atm and the pressure equilibrium constant ( $K_{p}$ ) is 9 atm, then the degree of dissociation is given as …
JEE Main 2026View solution →
$X_{2} (g) + Y_{2} (g) ⇌ 2 Z (g)$
$X_{2} (g)$ and $Y_{2} (g)$ are added to a 1 L flask and it is found that the system attains the above equilibrium at …
JEE Main 2026View solution →
Consider three metal chlorides $x, y$ and z , where x is water soluble at room temperature, $y$ is sparingly soluble in water at room temperature and z is soluble in hot water. $x, y$ and z are respectively
JEE Main 2026View solution →