15 Facts on HBr + NaOH: What, How To Balance & FAQs

Hydrogen Bromide, HBr, and Sodium Hydroxide, NaOH are two inorganic compounds. Let us explore how both react with each other to produce interesting products. 

HBr, a Lewis Acid. Its aqueous solution is widely used for the preparation of bromide compounds. In contrast, NaOH, also known as Caustic soda, can be commonly found in detergents or soaps. Due to their basic nature, both react with each other to obtain salt and water.

This article is going to stress the reaction between HBr + NaOH to obtain information about products and reaction mechanisms. Besides, it will address commonly-asked questions about these two compounds, like reaction enthalpy and ionic equations.

What is the product of HBr and NaOH?

Sodium Bromide (NaBr) and Water (H₂O) are the products formed when Sodium Hydroxide (NaOH) reacts with Hydrogen Bromide (HBr).

NaOH + HBr —-> NaBr + H₂O

What type of reaction is HBr + NaOH

The HBr + NaOH reaction is classified as an acid-base neutralization reaction because the strong acid, Hydrogen Bromide (HBr) neutralizes the strong base, Sodium Hydroxide (NaOH).

How to balance HBr + NaOH

In order to balance HBr + NaOH reaction the following steps is considered:

• First, take a closer look at the general equation.

HBr + NaOH —-> NaBr + H₂O

•  Now, compare the total number of atoms present on both of reactant side and the product side of each element.

Elements	No of atoms on the reactant side	No of atoms on the product side
H	2	2
Br	1	1
O	1	1
Na	1	1

• If the number of atoms on both sides is different, stoichiometric coefficients must be added until both sides get equal.
• Here, the number of atoms is similar to five atoms.
• Therefore, the equation is already balanced, and it can be written as follows:

HBr + NaOH = NaBr + H₂O

HBr + NaOH titration

The purpose of titration of HBr + NaOH reaction is to determine the unknown concentration of HBr from the known concentration of NaOH, or vice-versa.

Apparatus

• Beaker
• Funnel
• Burette
• Volumetric flask
• Erlenmeyer flask
• Pipette
• Distilled Water
• Sodium Hydroxide (NaOH)
• Hydrobromic acid (HBr)
• Burette clamp
• Wash bottle
• Stirrer

Titre & Titrant

• NaOH will be used as a titrant as its concentration is known.
• HBr will be used as titre as its concentration will be determined.

Indicator

Phenolphthalein indicator (C₁₂H₁₄O₄) is used as the indicator in this acid-base reaction to determine the end-point.

Procedure

• First, document the molarity of NaOH on the record/datasheet.
• Prepare a 10 ml solution of NaOH in a clean beaker.
• In order to coat the surface and the entire burette with NaOH solution, add 5 ml solution into the burette.
• Now, pour the solution till the 0 mark in the burette and allow the free flow of solutions by opening the stopcock. This ensures no air bubbles are trapped inside the burette.
• Fill the burette to 0 levels or record the initial reading where the NaOH solution stands.
• Take 10 ml (V_HBr) HBr solution using a pipette in a conical/ Erlenmeyer flask.
• Add 3 drops of phenolphthalein indicator into the acid solution.
• Place the flask under the barrette and perform titration with NaOH slowly.
• Add base until the solution color turns from colorless to pink. The pink coloration has to persist for 30 sec.
• The volume at which the color persists for 30 sec indicates the titration endpoint.
• Record the final burette reading. Repeat the process with the new burette volume 3 to 5 times.
• The strength of the HBr solution can be derived from the following equation-

V_NaOH * S_NaOH = V_HBr * S_HBr

HBr + NaOH net ionic equation

The reaction between HBr & NaOH gives the following ionic equation:

H⁺ + OH^– —-> H₂O

• HBr is a Strong Acid that completely ionizes in the aqueous solutions.

HBr_(aqueous) —> H⁺ + Br^–

• NaOH is a Strong base, and it completely dissociates in aqueous solutions.

NaOH_(aqueous) —-> Na⁺ + OH^–

• Therefore, the complete ionic reaction is written as follows-

H⁺ + Br^– + Na⁺ + OH^– —-> H₂O + Na⁺ + Br^–

• After canceling the similar ions (Na⁺ & Br^–) from both sides, the final equation is derived.

HBr + NaOH conjugate pairs

The reaction HBr + NaOH gives the conjugate pairs are-

• The conjugate pair of strong acid HBr = Br^– (Bromine ion).

• The conjugate pair of a strong base NaOH = H₂O (Water), and the Na⁺ is the spectator ion.

HBr and NaOH intermolecular forces

The intermolecular forces present in HBr+ NaOH are:

• HBr shows Dipole-dipole forces due to the presence of polar H & Br.
• HBr shows polar Dispersion forces.
• NaOH shows low dipole-dipole interaction.
• NaOH shows hydrogen bonds due to the presence of H.
• NaOH shows low polar Dispersion force.

HBr + NaOH reaction enthalpy

The standard reaction enthalpy of HBr + NaOH is -96.52 KJ/ mol. The enthalpy is calculated as follows-

Reactants/ Products	Enthalpy of formation
HBr(g)	-36.23 KJ/ mol
NaOH(aq)	-470.11 KJ/ mol
NaBr(s)	-361.06 KJ/ mol
H2O(g)	-241.8 KJ/ mol

NaOH + HBr —-> NaBr + H₂O

• ΣΔH⁰f_(reactants) = (-470.11 – 36.23) = -506.34 KJ/ mol
• ΣΔH⁰f_(products) = (-361.06 -241.8) = -602.86 KJ/ mol
• As, ΔH⁰f_(reaction) = ΣΔH⁰f_(products) – ΣΔH⁰f_(reactants)
• ΔH⁰f_(reaction) = -96.52 KJ/ mol

Is HBr + NaOH a buffer solution

The mixture of HBr + NaOH is not a buffer solution because NaOH is a strong base and HBr is not the conjugate pair of it.

Is HBr + NaOH a complete reaction

The reaction HBr + NaOH is a complete reaction as the product NaBr completely dissociates in water.

Is HBr + NaOH an exothermic or endothermic reaction

The reaction of HBr with NaOH is an exothermic reaction because the reaction HBr + NaOH resulted in strong bond formation that releases energy to the surroundings (ΣΔH⁰f_(reactants) > ΣΔH⁰f_(products)).

Is HBr + NaOH a redox reaction

The reaction HBr & NaOH is not a redox reaction because there is no change in the oxidation states of participating molecules was seen.

Is HBr + NaOH a precipitation reaction

HBr + NaOH reaction is not a precipitation reaction because the product, NaBr, easily dissolves in water.

Is HBr + NaOH reversible or irreversible reaction

HBr + NaOH reaction is irreversible because the reactants, HBr and NaOH, completely dissociate in the aqueous solution, leaving no residue.

Is HBr + NaOH displacement reaction

The reaction HBr + NaOH is considered a double-displacement reaction as both Br^– and OH^– ion interchanges their position.

Conclusion :

The reaction between Hydrogen Bromide and Sodium Hydroxide gives detailed insights into the acid-base reaction. NaOH is widely used in Chemical pulping, and cleaning agents. The product NaBr mainly use as a disinfectant and in the Petroleum industry.