Hydrobromic acid (HBr) is one of the strongest mineral acids and Magnesium Oxide (MgO) is a basic oxide. Let us study the reaction of HBr+ MgO in detail.
HBr is produced by reacting Bromine gas, Sulfur dioxide and Water. HBr is participates in anti-Markovnikov hydrohalogenation (Markovnikov’s rule) of alkenes. MgO exists as a white solid mineral powder which hygroscopic in nature. MgO possesses high chemical and physical stability at high temperatures.
In this following article, we will learn some important aspects of HBr+ MgO such as balancing chemical equation, enthalpy, type of reaction in greater depth.
What is the product of HBr and MgO?
HBr+ MgO react to form Magnesium bromide (MgBr2) and Water. The chemical equation is as follows:
MgO + 2HBr => MgBr2 + H2O
What type of reaction is HBr + MgO?
The reaction of HBr+ MgO is acid-base neutralization reaction because HBr is a strong acid and MgO is a strong basic oxide which on reacting produce the respective salt and water.
How to balance HBr + MgO?
The unbalanced chemical equation for HBr+ MgO is
- MgO + HBr => MgBr2 + H2O
- The reaction of HBr+ MgO is balanced using following steps:
- Firstly, note down the number of individual chemical species on the reactant side (LHS) and product side (RHS)
| Element | No. of atoms on reactant side (LHS) | No. of atoms on product side (RHS) |
|---|---|---|
| Mg | 1 | 1 |
| O | 1 | 1 |
| H | 1 | 2 |
| Br | 1 | 2 |
- Secondly, as per the number of species of LHS and RHS multiply by the appropriate stoichiometric coefficient. In this case HBr on LHS is multiplied 2.
- The final balanced chemical equation is as follows:
- MgO + 2HBr => MgBr2 + H2O
HBr + MgO titration
HBr+ MgO titration can be done in the following procedure,
Apparatus used
- Burette
- Pipette
- Conical flask
- Volumetric flask
Indicator used
- Phenolphthalein indicator is used for this titration. It turns colorless in acidic solution while in basic solution it turns pink.
Procedure
- MgO is sparingly soluble in water and the direct titration is not feasible. Hence for the quantification ‘Back titration’ approach is convenient.
- A known concentration of HBr and NaOH is prepared.
- NaOH is taken as the burette solution.
- In a conical flask, unknown amount of MgO is taken and dissolved in excess amount of HBr of known concentration
- Phenolphthalein indicator is added (approximately 2-3 drops)
- The solution in the conical flask is titrated against NaOH until the end point appears i.e., when the solution turns colorless to pink.
- Amount of excess HBr can be calculated from the amount of NaOH consumed. Following formula is used-
- VHBr* SHBr= VNaOH* SNaOH where (V is volume and S is concentration)
- In this way, we can calculate the amount of HBr required for the neutralization MgO by the means of back calculation.
HBr + MgO net ionic equation
The net ionic equation of HBr+ MgO is
- Mg2+(aq)+O2-(aq)+2H+(aq)+2Br–(aq)=>Mg2+(aq)+2Br–(aq)+H+(aq)+OH–(aq)
HBr + MgO conjugate pairs
HBr+ MgO reaction has the following conjugate pairs,
- The conjugate pair of HBr is Br– (conjugate base) because HBr is a strong acid and donates a proton.
- There’s no conjugate pair of MgO to exist due to it being a metal oxide.
HBr and MgO intermolecular forces
HBr+ MgO reaction has the following intermolecular classes,
- The intermolecular forces present in HBr is dipole-dipole forces.
- MgO molecule is held together by ionic bonding.
HBr + MgO reaction enthalpy
The reaction enthalpy of HBr+ MgO is -91.94 kJ mol-1, which is due to the high enthalpy of hydration exhibited by Mg2+ ion.
Is HBr + MgO a buffer solution?
HBr+ MgO is not a buffer solution because HBr is a strong acid, and buffer requires a weak acid and its conjugate base to maintain the pH.
Is HBr + MgO a complete reaction?
HBr+ MgO is a complete reaction because it takes place in forward direction and no excess HBr or MgO remains as reactants.
Is HBr + MgO an exothermic or endothermic reaction?
HBr+ MgO is an exothermic reaction. The reaction enthalpy of the reaction is -91.94 kJ mol-1 . The negative value of enthalpy represents the release of energy in the form of heat during reaction, hence the reaction is exothermic in nature.
Is HBr + MgO a redox reaction?
HBr+ MgO is not a redox reaction because there is no change in the oxidation states of the ions involved.
Is HBr + MgO a precipitation reaction?
HBr+ MgO is not a precipitation reaction because the product formed MgBr2 gets dissolved in the water and acid quite easily.
Is HBr + MgO reversible or irreversible reaction?
HBr+ MgO is an irreversible reaction because it is unidirectional in nature.
Is HBr + MgO displacement reaction?
HBr+ MgO is a double displacement reaction because O2- is getting replaced by Br– and Mg2+ by H+ to form MgBr2 as a salt and water.
Conclusion:
Hydrobromic acid (HBr) and Magnesium oxide (MgO) react to form Magnesium bromide and water. HBr+ MgO is a typical acid-base neutralization reaction. Magnesium bromide is used as a catalyst in many reactions, tranquilizer, and a mild sedative.
Hello…. I am Vishakha Awalegaonkar. I have done my Master’s in Analytical Chemistry. Currently, I am working for a leading Company in the consumer health sector. Apart from that, I am also a Japanese language trainer. Feel free to reach me on LinkedIn:
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