Question

It takes 45.60 mL of a 0.225 M hydrochloric acid solution to react completely with 25.00 mL of calcium hydroxide in this reaction below, what is the molar concentration of the calcium hydroxide solution?
2HCl(aq) + Ca(OH)2(aq)!CaCl2(aq) + 2H2O(l)

Answer 1

Answer:

Molar concentration of the calcium hydroxide solution = 0.2052 M

Explanation:

Volume of HCl = 45.60 mL  = 0.0456 L

Molar concentration of HCl = 0.225 M

Volume of Ca(OH)2 = 25.00 mL  = 0.025 L

No. of moles of HCl = (0.225 M)*(0.0456 L)   = 0.01026 mol

As we know

2 moles of HCl require 1 mole of Ca(OH)2, hence, .01026 moles of HCl will need 0.5*(0.01026) = 0.00513 moles of Ca(OH)2

Molar concentration of Ca(OH)2 = [(0.00513 mol)/(0.025 L)]   = 0.2052 M

Answer 2

Given :

It takes 45.60 mL of a 0.225 M hydrochloric acid solution to react completely with 25.00 mL of calcium hydroxide in the given reaction.

2HCl(aq) + Ca(OH)2(aq) --> CaCl2(aq) + 2H2O(l)

To Find :

The molar concentration of the calcium hydroxide solution.

Solution :

From given equation 2 mole of hydrochloric acid react with 1 mole of calcium hydroxide.

So,

$2M_1V_1 = M_2V_2\\\\2\times 0.225 \times 45.60 = M_2 \times 25 \\\\M_2 = \dfrac{20.52}{25}\\\\M_2 = 0.8208 \ M$

Therefore, molar concentration of the calcium hydroxide solution is 0.8208 M.