Question

Suppose that the stomach contains 0.200l of 0.05m hcl. what mass of the antacid mg(oh)2 is required to completely neutralize all of the hcl

Answer 1

1) Recognize the balanced equation is:

2HCl + Mg(OH)2 = MgCl2 + 2HOH

2) Find moles of HCl

(0.05moles/1L)(.200L) = .01 moles HCl

3) Use conversions to find moles of Mg(OH)2.

(.01mol HCl * 1mol Mg(OH)2)/ 2mol HCl =.005 mol Mg(OH)2

4) .005 * 58.32 (the molar mass) = .2916g Correct sig figs = 0.29g Mg(OH)2