Question

0.74g Ca(OH)2 is dissolved in water to give 200ml solution at 298K. The hydrogen ion concentration in the solution is :

Answer 1

given, 0.74g Ca(OH)2 is dissolved in water to give 200mL solution at 298K.

mass of Ca(OH)2 = 0.74g

molar mass of Ca(OH)2 = 40 + (16 + 1) × 2

= 40 + 34 = 74g/mol

so, number of moleof Ca(OH)2 = 0.74/74 =0.01

now, molarity = number of moles of Ca(OH)2/volume of solution in L

= {0.01/200} × 1000 = 0.05M

Ca(OH)2 dissociate ,

so, concentration of Ca(OH)2 = 2 × concentration of [OH-]

= 0.05 × 2 = 0.1M

we know ,

= 10^-14/0.1 = 10^-13 M

hence, concentration of hydrogen ion is 10^-13M

might help u dude