Final answer:
To determine if an equation is balanced, count the number of atoms of each element on both sides and ensure they are equal. In the case of PCl₅ + 4H₂O → H₃PO₄ + 3HCl, the equation is unbalanced due to the unequal number of hydrogen atoms.
Step-by-step explanation:
To find out if an equation is balanced, you should:
- Count the number of atoms of each element on both sides of the arrow.
- Verify that the charges on both sides of the equation are equal. However, this only applies to ionic equations where charges are present.
For the given equation PCl₅ + 4H₂O → H₃PO₄ + 3HCl, you can use these steps:
- Write the skeleton equation with the correct chemical formulas for the reactants and products.
- Balance the most complex substance first, typically starting with an element that appears in only one reactant and one product.
- Balance polyatomic ions as a unit if they are present on both sides of the equation.
- Balance the remaining atoms, possibly using fractional coefficients if necessary.
- Multiply the entire equation by the denominator to obtain whole number coefficients if fractional coefficients were used.
- Re-count the atoms to confirm that the equation is balanced.
For the example equation, counting the atoms reveals that phosphorus, chlorine, and oxygen are already balanced. However, there is an imbalance in hydrogen atoms. We have eight hydrogen atoms on the reactant side (from H₂O) and only six on the product side (from H₃PO₄ and HCl). Thus the equation is currently unbalanced.
A possible balanced equation for this chemical reaction could be:
PCl₅ + 4H₂O → H₃PO₄ + 5HCl
This yields a balanced equation with equal numbers of each type of atom on both sides of the equation.