Answer:
Yes ,The base neutralize all of the acid because it(base) is present in excess quantity .
Mg(OH)2 is in excess by 0.205 mole
Explanation:
The balanced equation is :
![Mg(OH)_{2} + 2 HCl \rightarrow MgCl_{2} + 2H_{2}O](https://tex.z-dn.net/?f=Mg%28OH%29_%7B2%7D%20%2B%202%20HCl%20%5Crightarrow%20MgCl_%7B2%7D%20%2B%202H_%7B2%7DO)
<u>Calculate the moles of Hydrochloric Acid and Magnesium hydroxide</u>
<u>For HCl</u>
![Moles = \frac{given\ mass}{molar\ mass}](https://tex.z-dn.net/?f=Moles%20%3D%20%5Cfrac%7Bgiven%5C%20mass%7D%7Bmolar%5C%20mass%7D)
Given mass = 20.0 g
Molar mass of HCl = 36.5 g/mol
![Moles = \frac{20}{36.5}](https://tex.z-dn.net/?f=Moles%20%3D%20%5Cfrac%7B20%7D%7B36.5%7D)
<em>mole of HCl</em> = <em>0.55 </em>
<u>For Mg(OH)2</u>
Given mass = 28.0 g
Molar mass of Mg(OH)2 = 58.3 g/mol
![Moles = \frac{28}{58.3}](https://tex.z-dn.net/?f=Moles%20%3D%20%5Cfrac%7B28%7D%7B58.3%7D)
<em>mole of Mg(OH)2 = 0.48</em>
According to the balanced equation ,
![Mg(OH)_{2} + 2 HCl \rightarrow MgCl_{2} + 2H_{2}O](https://tex.z-dn.net/?f=Mg%28OH%29_%7B2%7D%20%2B%202%20HCl%20%5Crightarrow%20MgCl_%7B2%7D%20%2B%202H_%7B2%7DO)
1 mole of Mg(OH)2 would require = 2 mole of HCl for neutralisation
So,
0.48 mole of Mg(OH)2 would require = 2(0.48) = 0.96 mol
<u>HCl needed for complete neutralisation = 0.96 mole</u>
<u>Available HCl = 0.55 mole</u>
HCl is less by = 0.96 -0.55 = 0.41 mole
So,
Mg(OH)2 is in excess by = 0.41/2 mole [because <u>1</u> HCl =<u> 2</u> Mg(OH)2]
= 0.205
Here HCl is less than need and Mg(OH)2 is in excess.