HBr (aq) + NaOH (aq) → H2O (l) + NaBr (aq)
The reaction is a neutralization reaction, in which an acid and a base react to form a salt and water. The products, water and sodium bromide, are both soluble in water, so the reaction takes place in a single phase.
The coefficients in the equation are determined by the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. In this case, there is one HBr molecule, one NaOH molecule, two H2O molecules, and one NaBr molecule. Therefore, the coefficients are 1, 1, 2, and 1, respectively.
