Question

What mass of $Mg{\left( {OH} \right)_2}$ is produced when 100 mL of 0.42 M $Mg{(N{O_3})_2}$ is added to excess NaOH solution?

Answer 1

Hint : In the given question firstly we have to define what exactly is the magnesium hydroxide and how can we determine it and give the proper definition and the characteristics of it. Like we can say that we can find the moles in the problem and then multiply it with molecular mass.
Complete Step By Step Answer:
The given question statement asks about the magnesium hydroxide and the main concepts of the molecules of the $Mg{\left( {OH} \right)_2}$ and the mass of the $Mg{\left( {OH} \right)_2}$ obtained in the equation. Which should be determined in a step by step process.The compound of the Magnesium hydroxide is the inorganic compound and the chemical formula of the compound is $Mg{\left( {OH} \right)_2}$ . It also occurs in nature as in the mineral form of brucite. It is also a white solid with low solubility in water which is $({K_{sp}}\; = {\text{ }}5.61 \times {10^{ - 12}})$ . We can also say that the Magnesium hydroxide is a common component of antacids, such as milk of magnesia.
Step 1:
We have to use the formula that the Mass= molar mass*moles
Now the molar mass of the $Mg{\left( {OH} \right)_2}$ :
$= 24 + 2 \times 16 + 2 \times 1$
$= 58g$
Step 2:
Now the mass of the $Mg{\left( {OH} \right)_2}$ which is formed would be :
$= 58 \times 0.042 \\\ = 2.436g \\\$
Therefore we can say that the total weight would be $2.436g$ .

Note :
Magnesium hydroxide is used in suspension as either an antacid or a laxative, depending on concentration. As an antacid, magnesium hydroxide is dosed at approximately 0.5–1.5 g in adults and works by simple neutralization, by which the hydroxide ions from the $Mg{\left( {OH} \right)_2}$ combine with acidic ${H^ + }$ ions produced in the form of hydrochloric acid by parietal cells in the stomach, to produce water.