Hydrogen bromide (HBr) or hydrobromic acid is a strong acid whereas Calcium chloride (CaCl2) is an inorganic salt. Let us discuss the reaction between: HBr + CaCl2.
HBr is a strong mineral acid used in preparation of inorganic bromides and also organobromine compounds. Calcium chloride is a white crystalline salt which is highly soluble in water. CaCl2 is hygroscopic in nature.
In this article, we will learn about the product, type of the reaction, balanced chemical equation, and various other facts about the reaction between HBr and CaCl2.
What is the product of HBr + CaCl2?
Calcium bromide(CaBr2) and hydrogen chloride(HCl) are formed after the reaction between aqueous hydrobromic acid and calcium chloride.
CaCl2 + HBr = CaBr2 + HCl
What type of reaction is HBr + CaCl2?
The reaction HBr + CaCl2 is a metathesis reaction which is also known as a double displacement reaction.
How to balance HBr + CaCl2?
The reaction CaCl2 + HBr = CaBr2 + HCl, is not yet balanced.
We use the following steps to balance the above reactions:
- We use variables such as a, b, c and d to represent the unknown coefficient for the reactants and the products.
- aCaCl2 + bHBr = cCaBr2 + dHCl
- The coefficients are then equated after rearranging the similar elements together.
- After rearranging according to their stoichiometric proportions, we get:
- Ca=a=c ; Cl=2a=d ; H=b=d ; Br=b=2c
- Now Gaussian elimination method is used for coefficient value determination, we get:
- a=1 ; b=2 ; c=1 ; d=2
- Thus the balanced chemical equation is
- CaCl2 + 2HBr = CaBr2 + 2HCl
HBr + CaCl2 titration
Titration between HBr and CaCl2 is not possible. A strong acid HCl is formed at the end of this reaction which makes it impossible to calculate the strength and unknown concentration of the solution.
HBr + CaCl2 net ionic equation
The net ionic equation for HBr + CaCl2 is :
Ca2+ (aq.) +2Cl–(aq.) + 2H+(aq.) + 2Br–(aq.) = Ca2+ (aq.) + 2Br–(aq.) + 2H+(aq.) + 2Cl–(aq.)
The net ionic equation is derived by following these steps –
- First step is to mention the chemical states of the compounds in the equation:
- CaCl2 (aq.) + 2HBr(aq.) = CaBr2 (aq.) + HCl(aq.)
- Then the corresponding compounds are split into their ionic forms as follows
- Ca2+ (aq.) +2Cl–(aq.) + 2H+(aq.) + 2Br–(aq.) = Ca2+ (aq.) + 2Br–(aq.) + 2H+(aq.) + 2Cl–(aq.)
- Hence the net ionic equation is:
- Ca2+ (aq.) +2Cl–(aq.) + 2H+(aq.) + 2Br–(aq.) = Ca2+ (aq.) + 2Br–(aq.) + 2H+(aq.) + 2Cl–(aq.)
HBr + CaCl2 conjugate pairs
The conjugate pair for HBr and CaCl2 are listed below:
- The conjugate acid for HBr is Br– .
- CaCl2 does not have any conjugate pair since it is an inorganic salt.
HBr + CaCl2 intermolecular forces
The intermolecular forces in HBr + CaCl2 are listed below:
- HBr is a polar molecule thus it has dipole-dipole interaction between the ions.
- Cacl2 is an inorganic salt having electrostatic force of interaction between the ions.
HBr + CaCl2 reaction enthalpy
The overall enthalpy of the reaction between -67.56 KJ/mol.
| Molecule | Enthalpy (KJ/mol) |
|---|---|
| HBr | -36.23 |
| CaCl2 | -877.1 |
| CaBr2 | -682.8 |
| HCl | -167.16 |
- The formula for calculation of enthalpy is = (Total Enthalpy of products – Total Enthalpy of reactants)
- =[-877.1+(-36.23×2)] – [ -682.8+(-167.16×2)] KJ/mol
- =-67.56 KJ/mol
Is HBr + CaCl2 a buffer solution?
HBr + CaCl2 cannot form a buffer solution. This is because of the presence of the strong acid HBr, since buffer solutions contain weak acid in them.
Is HBr + CaCl2 a complete reaction?
HBr + CaCl2 is a complete reaction since two products i.e., CaBr2 and HCl are formed at the end of the reaction.
Is HBr + CaCl2 an exothermic or endothermic reaction?
The reaction HBr + CaCl2 is an exothermic reaction since a negative enthalpy value of -67.56 KJ/mol is obtained at the end of the reaction.
Is HBr + CaCl2 a redox reaction?
HBr + CaCl2 is not a redox reaction. This is because the oxidation states of the elements do not change even after completion of the reaction as shown below, where the Roman symbols in the superscript shows the oxidation states of the elements.
CaIICl2I + 2HIBrI → CaIIBr2I + 2HIClI
Is HBr + CaCl2 a precipitation reaction?
HBr + CaCl2 is not a precipitation reaction because CaBr2 is soluble in HCl thus no precipitation is observed.
Is HBr + CaCl2 reversible or irreversible reaction?
HBr + CaCl2 is an irreversible reaction because after the completion of the reaction CaBr2 and HCl are obtained which do not react back to form the reactants.
Is HBr + CaCl2 displacement reaction?
HBr + CaCl2 is a double displacement reaction. Here chloride ion is displaced by bromine ions in Cacl2 and bromine ions are replaced by chloride ions in HBr.
Conclusion
Calcium chloride is a white crystalline inorganic salt that is highly soluble in water. It reacts with strong hydrobromic acid to form a salt calcium bromide along with another strong acid i.e, hydrochloric acid.
Hello… , I am Bhaswati Ghose. I have completed my master’s from St. Xavier’s College, Ranchi. My specialization subject was organic chemistry. I’m working as a subject matter expert in chemistry.