A 50.0 ml sample of ca (oh) 2 is neutralized by 300.0 ml of hcl solution with a ph of 1.3. calculate the molarity of the ca (oh) 2 solution. 1. 0.50 m 2. 1.0 m 3. 0.05 m 4. 0.30 m 5. 0.15 m

The molarity of the Ca (OH) 2 solution is calculated as follows

find the concentration of HCl used from the Ph

that is PH = - log H + = 1.3

H + = 10^-1.3 = 0.05 M

the moles of HCl = molarity x volume/1000

= 0.05 x 300/1000=0.015 moles

write the reaction equation

that is Ca (OH) 2 + 2HCl=CaCl2 + 2H20

by use of reacting ratio between Ca (OH) 2 to HCl (1:2) the moles of Ca (OH) 2 is = 0.015 x1/2=7.5 x10^-3 moles

molarity is therefore = moles / volume in liters

= { (7.5x10^-3) / 50} x1000 = 0.15 M (answer 5)