A student is given an antacid tablet that weighs 5.8400 g. The tablet is crushed and 4.2800 g of the antacid is added to 200. mL of simulated stomach acid. It is allowed to react and then filtered. It is found that 25.00 mL of this partially neutralized stomach acid required 11.6 mL of a NaOH solution to titrate it to a methyl red end point. It takes 29.0 mL of this NaOH solution to neutralize 25.00 mL of the original stomach acid. How much of the original 200. mL of stomach acid (in mL) is neutralized by the 4.2800 g crushed sample of the tablet

Explanation:

Given that:

mass of the antacid tablet = 5.8400 g

required mass of the antacid tablet = 4.2800 g was added to 200. mL of simulated stomach acid.

The amount of the  original 200. mL of stomach acid (in mL) needed to  neutralize the 4.2800 g crushed sample of the tablet can be calculated as:

= 11.6 mL of NaOH × 25.00 mL /29.0 mL NaOH

= 10.00 mL original stomach acid

Now; since it requires 11.6  mL of  NaOH o neutralize 10.00 mL of  original acid , then:

the antacid neutralized = 200 mL - 10.00 mL

the antacid neutralized = 190.00 mL

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-