Question

Magnesium hydroxide, the active ingredient in milk of magnesia, neutralizes stomach acid, primarily hcl, according to the reaction: mg(oh)2(aq) + 2 hcl(aq) → h2o(l) + mgcl2(aq) how much hcl in grams can be neutralized by 5.50 g of mg(oh)2 ? express your answer in grams to two decimal places.

Answer 1

6.88 grams of hydrochloric acid (HCl) can be neutralized by 5.50 g of magnesium hydroxide, Mg(OH)2.

FURTHER EXPLANATION

This problem is an example of a simple stoichiometry problem. To determine the mass of hydrochloric acid neutralized, the following steps must be done:

1. Balance the chemical equation.
2. Convert the mass of magnesium hydroxide to moles using the molar mass.
3. Use the stoichiometric ratio from the balanced chemical reaction to determine how many moles of hydrochloric acid are formed.
4. Convert the moles of hydrochloric acid to mass using its molar mass.

Applying the steps above to the problem:

STEP 1: The balanced chemical equation is:

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

STEP 2: The molar mass of Mg(OH)₂ is 58.3197 g/mol. The moles of Mg(OH)₂ can be calculated as follows:

$moles \ Mg(OH)_{2} = 5.50 \ g Mg(OH)_{2} \times \frac{1 \ mol}{58.3197 \ g \ Mg(OH)_{2}}\\\\moles \ Mg(OH)_{2} = 0.09431 \ mol$

STEP 3: The stoichiometric ratio of Mg(OH)₂ and HCl is 1:2. This can be used as a conversion factor to get the number of moles of HCl:

$moles \ HCl = 0.09431 \ mol \ Mg(OH)_2 \times \frac{2 \ mol \ HCl}{1 \ mol \ Mg(OH)_{2}}\\\\moles \ HCl = 0.18862 \ mol$

STEP 4: The molar mass of HCl is 36.46094 g/mol and this can be used to convert from moles HCl to grams HCl.

$mass \ HCl \ = 0.18862 \ mol \ HCl \times \frac{36.46094 \ g}{1 \ mol \ HCl}\\mass \ HCl = 6.8788 \ g$

Since the given has three significant figures, the final answer must also have 3 significant figures. Therefore,

$\boxed {\boxed {mass \ HCl = 6.88 \ g}}$

Learn More

• Neutralization Reaction  brainly.com/question/4455839
• Titration brainly.com/question/186765

Keywords: stoichiometry, acid, base, moles

Answer 2

For every 1 molecule of Magnesium hydroxide or Mg(OH)2 there will be 2 molecules of HCl neutralized.
If molar mass of magnesium hydroxide is 58.3197g/mol, the amount of mol in 5.50 g magnesium hydroxide should be: 5.50g/ (58.3197g/mol)= 0.0943mol.
Then, the amount of HCl molecule neutralized would be: 2* 0.0943mol= 0.18861 mol

If molar mass of HCl is 36.46094 g/mol, the mass of the molecule would be: 0.18861 mol* 36.46094g/mol = 6.88grams