Respuesta :
Answer: The mass of calcium hydroxide reacted is 28.305 g
Explanation:
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] .....(1)
Given mass of phosphoric acid = 25 g
Molar mass of phosphoric acid = 98 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of phosphoric acid}=\frac{25g}{98g/mol}=0.255mol[/tex]
The chemical equation for the reaction of phosphoric acid and calcium hydroxide follows:
[tex]3Ca(OH)_2+2H_3PO_4\rightarrow Ca_3(PO_4)_2+6H_2O[/tex]
By Stoichiometry of the reaction:
2 moles of phosphoric acid reacts with 3 moles of calcium hydroxide.
So, 0.255 moles of phosphoric acid will react with = [tex]\frac{3}{2}\times 0.255=0.3825moles[/tex] of calcium hydroxide.
Now, calculating the mass of calcium hydroxide from equation 1, we get:
Molar mass of calcium hydroxide = 74 g/mol
Moles of calcium hydroxide = 0.3825 moles
Putting values in equation 1, we get:
[tex]0.3825mol=\frac{\text{Mass of calcium hydroxide}}{74g/mol}\\\\\text{Mass of calcium hydroxide}=28.305g[/tex]
Hence, the mass of calcium hydroxide reacted is 28.305 g
