# Write and balance the equation for the reaction of hydrochloric acid (H2SO4) and sodium hydroxide to produce sodium sulfate and water.

The balanced equation for the reaction of H2SO4 and sodium hydroxide that produces sodium sulfate and water is H2SO4 + 2(NaOH) -----> Na2SO4 + 2(H2O).

First, we should recognize that the formula (H2SO4) is not hydrochloric acid. The root "chlor" in "hydochloric acid" denotes the presence of chlorine, which is not present in H2SO4. Hydrochloric acid is HCl. H2SO4 is sulfuric acid.

We need to combine sulfuric acid and sodium hydroxide to produce sodium sulfate and water.

H2SO4 + NaOH   ---->   Na2SO4 + H2O

This is the skeleton equation; it shows us what the reactants and products are, but not their coefficients, i.e. how many of each molecule we need to complete the reaction.

In order to balance the equation, the number of atoms must be exactly the same on both sides. Currently, on the reactant side we have:

3H, 1S, 5O, 1Na

And on the reactant side we have:

2H, 1S, 5O, 2Na

The sodium atoms and the hydrogen atoms don't match. Balance the sodium first. It's usually much easier if you save hydrogen and oxygen for last. To balance the sodium, we have to increase the number of sodium hydroxide molecules in the reactants:

H2SO4 + 2(NaOH)   ---->   Na2SO4 + H2O

Now we have 4H, 1S, 6O, 2Na and 2H, 1S, 5O, 2Na.

Everything matches except the hydrogen and oxygen in the products. Fortunately we're missing exactly 2 hydrogens and 1 oxygen: one H2O molecule.

H2SO4 + 2(NaOH)   ---->   Na2SO4 + 2(H2O)

4H:1S:6O:2Na ----> 4H:1S:6O:2Na

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