If 13.50 grams of hydrochloric acid (HCl) are reacted with excess calcium carbonate, how many grams of water are produced?

3.3g

Explanation:

Given parameters:

Mass of HCl  = 13.5g

Unknown:  

 Mass of water produced  = ?

Solution:

The reaction equation is shown below;

         2HCl   +  CaCO₃  →  CaCl₂  +  CO₂  + H₂O

To solve this problem, let us find the number of moles of the given specie first then we can use that to find the mass of the unknown water.

  Number of moles  =

           Molar mass of HCl  = 1 + 35.5  = 36.5g/mol

  Number of moles of HCl  =   = 0.37mol

From the balanced chemical reaction;

      2 mole of HCl will produce 1 mole of H₂O

     0.37mole of HCl will produce   = 0.19mole of H₂O

So to find the mass of H₂O;

   Mass  = Number of moles x molar mass

         Molar mass of H₂O  = 2(1) + 16  = 18g/mol

  Mass of H₂O  = 0.19 x 18  =3.3g

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.