Question

What is the molarity of a solution of calcium hydroxide,

Ca(OH)2, if 353 mL is neutralized with 45.96 mL of a 0.425 M
HCl?

Answer 1

To find the molarity of the solution of calcium hydroxide, use the balanced chemical equation and the volume and molarity of the hydrochloric acid used in the reaction. The molarity of the solution is 0.0276 M.

Step-by-step explanation:

To calculate the molarity of the solution of calcium hydroxide (Ca(OH)2), we can use the balanced chemical equation and the volume and molarity of the hydrochloric acid (HCl) used in the neutralization reaction.

The balanced equation is: Ca(OH)2 + 2HCl -> CaCl2 + 2H2O

From the equation, we can see that 2 moles of HCl react with 1 mole of Ca(OH)2. Therefore, the number of moles of Ca(OH)2 in the solution can be calculated as:

moles of Ca(OH)2 = (volume of HCl x molarity of HCl) / 2

Plugging in the values, we get:

moles of Ca(OH)2 = (0.04596 L x 0.425 M) / 2 = 0.009758 mol

The molarity of the solution of Ca(OH)2 is then:

Molarity = moles of Ca(OH)2 / volume of solution (in L)

Molarity = 0.009758 mol / 0.353 L = 0.0276 M

Answer 2

The molarity of the solution of calcium hydroxide is approximately 0.055 M.

Step-by-step explanation:

To find the molarity of the solution of calcium hydroxide (Ca(OH)2), we can use the information given in the question. The volume of the calcium hydroxide solution is 353 mL and it is neutralized with 45.96 mL of a 0.425 M HCl solution.

First, we need to calculate the number of moles of HCl used:

Moles of HCl = Volume of HCl solution (in L) x Molarity of HCl solution

Moles of HCl = 0.04596 L x 0.425 M = 0.0195 moles

Since HCl and calcium hydroxide have a 1:1 mole ratio, the number of moles of calcium hydroxide is also 0.0195 moles. Now we can calculate the molarity of the calcium hydroxide solution:

Molarity of Ca(OH)2 solution = Moles of Ca(OH)2 / Volume of Ca(OH)2 solution (in L)

Molarity of Ca(OH)2 solution = 0.0195 moles / 0.353 L ≈ 0.055 M