Hydrochloric acid (HCl) and sodium hydroxide (NaOH) react to form water and sodium chloride (NaCl). If you have 2.87 g of HCl, 3.75 g of water, and 1.98 g of NaCl, how many grams of NaOH were reacted? Your answer should go to the hundredths place.

2.86g

Explanation:

Mass of HCl  = 2.87g

Mass of water  = 3.75g

Mass of NaCl  = 1.98g

Unknown:

Mass of NaOH reacted  = ?

Solution:

  The reaction expression is given as:

           HCl    +   NaOH   →   NaCl   +  H₂O

According to the law of conservation of mass, the mass of reactants and products must be the same.

   Mass of HCl   +   Mass of NaOH  = Mass of NaCl  +  Mass of H₂O

      2.87g + Mass of NaOH  = 1.98g + 3.75g

           Mass of NaOH  = 1.98g + 3.75g - 2.87g  = 2.86g