Demonstrate that the following chemical equation illustrates the conservation of mass in chemical reactions:?

Relative atomic masses : H = 1.01, O = 16.00, Na = 22.99, P = 30.97

Molar mass of NaOH = (22.99 + 16.00 + 1.01) g/mol = 40.00 g/mol
Molar mass of H₃PO₄ = (1.01×3 + 30.97 + 16.00×4) = 98.00 g/mol
Molar mass of Na₃PO₄ = (22.99×3 + 30.97 + 16.00×4) = 163.94 g/mol
Molar mass of H₂O = 1.01×2 + 16.00 = 18.02 g/mol

3NaOH + H₃PO₄ → Na₃PO₄ + 3H₂O

According to the stoichiometry of the above equation, consider 3 moles of NaOH reacts with 1 mole of H₃PO₄ to form 1 mole of Na₃PO₄ and 3 moles of H₂O.
Total mass of reactants consumed = 3(40.00 g) + (98.00 g) = 218.00 g
Total mass of products formed = (163.94 g) + 3(18.02 g) = 218.00 g

Total mass of reactants consumed = Total mass of the products formed
This demonstrates

Count the number of atoms in the reactants:
Na = 3
O = 7
H = 6
P = 1

Now count the number of atoms in the products:
Na = 3
O = 7
H = 6
P = 1

Atoms of each element have a fixed mass* . The total atoms of each element in the reactants equals the total atoms of each element in the products . Therefore mass of reactants = mass of products . Law of conservation of mass is proven.

* In this simple explanation , ignore isotopes.

time waster

new account / old stolen Q

report it

https://answers.yahoo.com/question/index?qid=20081217104404AAuZKAA