Calculate the concentration of an aqueous solution of Ca(OH)2Ca(OH)2 that has a pHpH of 12.11. Express your answer using two significant figures.

Concentration of  is

Explanation:

pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration.

According to stoichiometry,

2 mole of are produced by = 1 mole of

Thus 0.0129 moles of are produced by = moles of

The concentration of  is

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.