Respuesta :
Answer: The mass of water required is 18.52 g
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of magnesium hydroxide = 30.0 g
Molar mass of magnesium hydroxide = 58.32 g/mol
Plugging values in equation 1:
[tex]\text{Moles of magnesium hydroxide}=\frac{30.0g}{58.32g/mol}=0.5144 mol[/tex]
The given chemical equation follows:
[tex]Mg(OH)_2+2HCl\rightarrow MgCl_2+2H_2O[/tex]
By the stoichiometry of the reaction:
If 1 mole of magnesium hydroxide produces 2 moles of water
So, 0.5144 moles of magnesium hydroxide will react with = [tex]\frac{2}{1}\times 0.5144=1.0288mol[/tex] of water
Molar mass of water = 18 g/mol
Plugging values in equation 1:
[tex]\text{Mass of water}=(1.0288mol\times 18g/mol)=18.52g[/tex]
Hence, the mass of water required is 18.52 g
