How many miles of water would form from the reaction of exactly 58.3 grams of magnesium hydroxide

Answer 1

Writing out a balanced equation is the first step: Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O.

From this equation we see that the molar proportions of the reaction are 1 mole Mg(OH)₂ produces 2 moles of water. The mass of 58.3 grams of Mg(OH)₂ represents exactly 1 mole of the reactant, so complete reaction results in the formation of 2 moles of water. The molecular weight of water is 18, so the reaction produces 36 grams of water. The density of water is 1.0, and D = mass/volume. 1 g/ml = 36 grams/X ml, x = 36 milliliters. At room temperature, we know that 1 milliliter of water weighs 1 gram, so 36 grams of water will have a volume of 36 ml.

Answer 2

Assuming you are reacting the magnesium hydroxide with an acid, you would have the following reaction:

Mg(OH)₂ + 2HA ==> MgA₂ + 2H₂O for a monoprotic acid, or...

Mg(OH)₂ + H₂A ==> MgA + 2H₂O for a diprotic acid

So, from 1 moles Mg(OH)2, you obtain 2 moles H2O

58.3 g Mg(OH)₂ x 1 mole/58.3 g x 2 mole H₂O/mole Mg(OH)₂ = 2.00 moles H₂O