Respuesta :
Answer: The mass of calcium hydroxide that are present in the solution is 0.3256 grams.
Explanation:
To calculate the moles of a solute, we use the equation:
[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}[/tex]
We are given:
Volume of hydrochloric acid = 42.7mL = 0.0427 L (Conversion factor: 1 L = 1000 mL)
Molarity of the solution = 0.208 moles/ L
Putting values in above equation, we get:
[tex]0.208mol/L=\frac{\text{Moles of hydrochloric acid}}{0.0427L}\\\\\text{Moles of hydrochloric acid}=0.0088mol[/tex]
For the given chemical reaction:
[tex]Ca(OH)_2(aq.)+2HCl\rightarrow CaCl_2(aq.)+2H_2O(l)[/tex]
By Stoichiometry of the reaction:
2 moles of hydrochloric acid reacts with 1 mole of calcium hydroxide.
So, 0.0088 moles of hydrochloric acid will react with = [tex]\frac{1}{2}\times 0.0088=0.0044mol[/tex] of calcium hydroxide.
To calculate the mass of calcium hydroxide, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Moles of calcium hydroxide = 0.0044 moles
Molar mass of calcium hydroxide = 74 g/mol
Putting values in above equation, we get:
[tex]0.0044mol=\frac{\text{Mass of calcium hydroxide}}{74g/mol}\\\\\text{Mass of calcium hydroxide}=0.3256g[/tex]
Hence, the mass of calcium hydroxide that are present in the solution is 0.3256 grams.
0.325 grams of Ca(OH)₂ must be in the solution of HCl to neutralize a solution.
How we calculate moles from molarity?
Molarity of any solution is defined as:
M = n/V, where
n = no. of moles
V = volume
Given chemical reaction is:
Ca(OH)₂(aq) + 2HCl → CaCl₂(aq) + 2H₂O(l)
From the stoichiometry of the reaction, it is clear that:
2 moles of HCl = react with 1 mole of Ca(OH)₂
1 mole of HCl = react with 1/2 mole of Ca(OH)₂
Moles of HCl will be calculated by using the molarity formula and given data as:
Given concentration of HCl = 0.208M
Given volume of HCl = 42.7mL = 0.0427L
Moles of HCl = 0.208 × 0.0427 = 0.0088 moles
0.0088 moles of HCl = react with 0.0088 × 1/2 = 0.0044moles of Ca(OH)₂
Mass of Ca(OH)₂ will be calculated by using the formula:
n = W/M, where
W = required mass
M = molar mass = 72g/mole
W = 0.0044mole × 72g/mole = 0.325 grams
Hence, 0.325 grams of Ca(OH)₂ will be in the solution.
To know more about molarity, visit the below link:
https://brainly.com/question/17138838
