Question

Magnesium hydroxide, the active ingredient in milk of magnesia, neutralizes stomach acid, primarily HCl, according to the reaction in the following: Mg(OH)2(aq)+2HCl(aq)→2H2O(l)+MgCl2(aq) What mass of HCl, in grams, is neutralized by a dose of milk of magnesia containing 3.26 g of Mg(OH)2?

Answer 1

Answer:

4.076g of HCl is neutralized by a dose of milke of magnesia containing 3.26g of Mg(OH)2

Explanation:

Step 1: The balanced equation

Mg(OH)₂(aq) + 2 HCl(aq) ⇔ 2 H₂O(l) + MgCl₂(aq)

This means that for 1 mole of Magnesium hydroxide consumed, there i s consumed 2 moles of HCl and there is produced 1 mole of MgCl2 ( and 2 moles of H2O)

Step 2: Calculating moles of Mg(OH)2

moles of Mg(OH)2 = mass of Mg(OH)2 / Molar mass of Mg(OH)2

moles Mg(OH)2 = 3.26g / 58.32g/mole = 0.0559 mole Mg(OH)2

Step 3: Calculating moles of HCl

Since there is for 1 mole Mg(OH)2 consumed, there is consumed 2 moles of HCl

There is for each 0.0559 moles of Mg(OH)2, 2*0.0559 = 0.1118 moles of HCl consumed.

Step 4: Calculating mass of HCl

mass of HCl = moles of HCl x Molar mass of HCl

mass of HCl = 0.1118 moles * 36.46 g/mole

mass of HCl = 4.076 g

4.076g of HCl is neutralized by a dose of milke of magnesia containing 3.26g of Mg(OH)2