x mg of Mg ( OH ) 2 ( molar mass = 58 ) is required to be dissolved in 1.0 L of water to produce a pH of 10.0 at 298 K. The value of x is ________ mg. (Nearest integer) (Given : Mg ( OH ) 2 is ass

Question

x mg of Mg ( OH ) 2 ​ ( molar mass = 58 ) is required to be dissolved in 1.0 L of water to produce a pH of 10.0 at 298 K. The value of x is ________ mg. (Nearest integer) (Given : Mg ( OH ) 2 ​ is assumed to dissociate completely in H 2 ​ O )

TestHub · Accepted Answer

​ pH = 10 pOH = 4 [ OH − ] = 1 0 − 4 ​ no. of moles of OH − = 1 0 − 4 no. of moles of Mg ( OH ) 2 ​ = 2 1 0 − 4 ​ = 5 × 1 0 − 5 mass of Mg ( OH ) 2 ​ ​ = 5 × 1 0 − 5 × 58 × 1 0 3 mg = 2.9 ​

Chemistry - Ionic Equilibrium Question with Solution | TestHub

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