21 Facts on HBr+PbCrO4 : What, How to balance & FAQ

The purpose of chemical reaction is to be able to recognize chemical products. Let us see which type of reaction occurs in such a case.

Lead(2)Chromate is a strong oxidizing agent in which Pb exists in +2 oxidation state. It is less soluble in water but soluble in ammonia. It is a stable compound.While HBr is  colorless gas and used as a catalyst, it is a strong acid.

Now in this article we are going to learn about such properties like intermolecular forces, reaction enthalpy, buffer solution and so on.

What is the product of HBr + PbCrO₄ ?

HBr and PbCrO₄ when reacted form lead(2) bromide and chromium oxide and water.

• PbCrO₄ + 2HBr -> PbBr₂ + CrO₃ + H₂O

What type of reaction is HBr + PbCrO₄ ?

It is an acid base reaction or neutralization reaction.  In this reaction acidic salt, acidic oxide and water are formed. 

How to balance HBr and PbCrO₄ ?

HBr + PbCrO₄ reaction is balanced in the following steps-

• HBr + PbCrO₄ -> PbBr₂ + CrO₃ + H₂O
• In This following reaction both reactant and product must be present in equal amounts, stoichiometry of this reaction, 2 molecules of HBr multiply with H₂ and Br. 

2 HBr + PbCrO₄ -> PbBr₂ + CrO₃ + H₂O

HBr + PbCrO₄ Titration ?

PbBrO₄ compound is giving Acid-Base titration. There are following steps for this titration.

Apparatus

• Conical flask 
• Burette
• Volumetric flask
• Beaker
• Pippate 

Titrate and titrant

• HBr is used as a titrant because its concentration is known.
• PbCrO₄ concentration is unknown in the sample so it is used as titre.

Indicator

In this acid base titration we know the PbCrO₄ is an orange-yellow color compound. So, Methyl orange is used as an indicator because it changes the color of the acid.

Procedure

• Firstly weigh the sample of Lead Chromate and dissolve in cold water because it is less soluble in cold water and mix it well in conical flask.
• Now this sample is added into the burette.
• The titrant is taken into the pipette and poured into the conical flask.
• And drop wise the unknown sample is added to this conical flask and where reaction occurs.
• The indicator methyl orange is added to the conical flask where the color is changed and it becomes yellow to orange.
• And the endpoint occurs when the yellow color turns into orange .
• The above procedure is repeated 3 times for consistent readings.
• The concentration of solution is calculated by M1V1 = M2V2.

HBr + PbCrO₄ net ionic equation

The net ionic equation between HBr + PbCrO₄ is-

Pb⁺² (s) + CrO₄^-2 (s) + 2HBr^-1 (g)   →  Pb⁺² (s) + Br^-1 + CrO₃⁺⁶(s) + H₂O⁺¹ (aq)

• HBr is dissolved into the Bromine and Hydrogen ions.
• PbCrO₄ is dissolved into the Lead Ions and Chromium trioxide.
• And one molecule of water is also formed.

HBr and PbCrO₄ Conjugated pairs

HBr + PbCrO₄ there is only one conjugated pair available.

• The conjugate acid of H₂CrO₄  = HCrO₄

HBr + PbCrO₄ Intermolecular forces

HBr And PbCrO₄ reaction has following intermolecular forces

• HBr is containing  dipole – dipole force because hydrogen and bromine have differences in interaction. It also consists of hydrogen bonding and London dispersion forces.
• PbCrO₄ have strong ionic forces due to presence of CrO₄ and also have dipole dipole interaction.

HBr + PbCrO₄ reaction enthalpy

The standard enthalpy for the HBr +PbCrO₄ is around -150.3 kJ/mol. Brief enthalpy information is as follows-

• Lead(2)chromate =150.3 KJ/mol

• Hydrogen bromide = -75.13KJ/mol

• Lead(3) bromide = 150.3KJ/mol

• Chromium oxide = -150.3 Kj/mol

• Water= -150.3 KJ/mol

Is HBr + PbCrO₄ a buffer solution?

HBr+PbCrO₄ is a buffer solution because the nature of PbCrO₄ acts as a weak acid while PbBr₂ acts as a conjugate base that’s why it is a buffer solution. So, It maintain the pH of the solution.

Is HBr + PbCrO₄ a complete reaction ?

HBr + PbCrO₄ is a complete reaction because the product is completely formed and the water is released from it.

Is HBr + PbCrO₄ an exothermic reaction ?

HBr and PbCrO₄ is an exothermic in nature and the overall enthalpy is negative . Because it is a stable compound when they react together, a lot of heat is released due to bond breaking.

Is HBr + PbCrO₄ a Redox Reaction ? 

HBr + PbCrO₄ is not a redox type reaction because the oxidation state of both side  reactant and product are similar and the atoms do not change their state.

Is HBr + PbCrO₄ a Precipitation Reaction ?

HBr + PbCrO₄ reaction gives precipitation reaction because the product  exists in solid state in white color powdered form that is precipitate for this reaction ,which is insoluble in water.

Is HBr + PbCrO₄ a Reversible Reaction ?

HBr + PbCrO₄ reaction gives reversible reaction because it is an acid base reaction. These types of reactions can convert reactants to products. 

Is HBr and PbCrO₄ a Displacement reaction ?

HBr + PbCrO₄ reaction is a  double displacement reaction because the ions present in reaction are completely replaced to the product side.

• The hydrogen ions are combined with acid and form water molecules.
• The Bromine ion is combined with Pb⁺² ion and forms an acidic salt.

Conclusion

PbCrO₄ is an inorganic compound. It is hazardous in nature .It is less soluble in water but soluble in ammonia.It is a yellow color compound that is used in pigmentation. It has carcinogenic properties.It used in industries for coloring agents like paints, dye, ink.