3.55P - Chemistry: Molecular Nature Of Matter And Change

Question

Convert the following into balanced equations:When solutions of calcium chloride and sodium phosphate are mixed, solid calcium phosphate forms and sodium chloride remains in the solution. 

Step-by-Step Solution

Answer

This is an example of the double replacement reaction. All the balanced procedures are given in steps.

$2{\mathrm{Na}}_3{\mathrm{PO}}_4+3{\mathrm{CaCl}}_2\to 1{\mathrm{Ca}}_3{\left({\mathrm{PO}}_4\right)}_2+6\mathrm{NaCl}$

Step1. Overall equation.

The balanced equation is;

$2{\mathrm{Na}}_3{\mathrm{PO}}_4+3{\mathrm{CaCl}}_2\to 1{\mathrm{Ca}}_3{\left({\mathrm{PO}}_4\right)}_2+6\mathrm{NaCl}$

Above is the final balanced equations.

Step2. Stepwise balanced equation.

1. Starting with the most complicated formula: ${\mathrm{Ca}}_3{\left({\mathrm{PO}}_4\right)}_2$                                                           By putting 1 in front of it we are now fixing the number of Ca atoms and PO₄ groups. ${\mathrm{Na}}_3{\mathrm{PO}}_4+{\mathrm{CaCl}}_2\to 1{\mathrm{Ca}}_3{\left({\mathrm{PO}}_4\right)}_2+\mathrm{NaCl}$ 
2. Balance of Ca: Done by putting 3 in front of CaCl₂. ${\mathrm{Na}}_3{\mathrm{PO}}_4+3{\mathrm{CaCl}}_2\to 1{\mathrm{Ca}}_3{\left({\mathrm{PO}}_4\right)}_2+\mathrm{NaCl}$     
3. Balance of PO₄: By putting 2 in front of Na₃PO₄.                                                                               $2{\mathrm{Na}}_3{\mathrm{PO}}_4+3{\mathrm{CaCl}}_2\to 1{\mathrm{Ca}}_3{\left({\mathrm{PO}}_4\right)}_2+\mathrm{NaCl}$    
4. Balance of Na: By putting 6 in front of NaCl                                                                                     $2{\mathrm{Na}}_3{\mathrm{PO}}_4+3{\mathrm{CaCl}}_2\to 1{\mathrm{Ca}}_3{\left({\mathrm{PO}}_4\right)}_2+6\mathrm{NaCl}$ 
5. Putting Coefficient: Equation will be balanced, by checking                                                          Left-hand side and right-hand side total atom balanced or not.                                                   Now write the balanced equation.                                                                                                     $2{\mathrm{Na}}_3{\mathrm{PO}}_4+3{\mathrm{CaCl}}_2\to {\mathrm{Ca}}_3{\left({\mathrm{PO}}_4\right)}_2+6\mathrm{NaCl}$