Question

Question 5 1 pts You have a saturated solution of Ca(OH), in a flask, meaning there is some solid Ca(OH), sitting at the bottom of the aqueous solution. Which of the following will increase the Ca2+ concentration in solution? Adding water to the solution. Adding HCl(aq) to the solution. Adding KOH(aq) to the solution Adding more Ca(OH)2(s) to the flask,

Answer 1

Ans. By adding HCl (aq) to the saturated Ca(OH)2 solution, the following reaction occurs; Ca(OH)2 + 2 HCI CaCl2 + 2 H2O The CaCl2 is highly soluble in water. In the solution, the Ca2+ and Cl- ions will be present in addition to H+, OH-ions, and thus the concentration Ca2+ ions will increase in the solution. Moreover, on adding KOH(aq) there is high concentration of OH-ions in the solution, resulting in more possibility to form Ca(OH)2. As a result, Ca2+ ion concentration will not be increased. On adding Ca(OH)2, its amount will further increase in the bottom of the saturated solution and it remains insoluble in the solution. Thus, it doesn't affect the concentration of Ca2+ in the solution. Also, on adding water, dilution happens and volume of solution will increase. This will decreases the Ca2+ concentration in the solution. Thus, the correct option is B.