Question

A) write the correct charge balance equation for a solution containing 0.2 M AlPO4 and 0.1 M BaCl2

B) write the correct mass balance relationship for CH3CO2Na

Answer 1

A) Solution

Charge Balance equation

step 1 : positive = negative

step 2: We have to dissociate the given salts into corresponding negatively charged and positvely charged ions( including water because this is aq.solution)

step3: Dissociation gives the following ions

Al^{3+ ,} PO₄^3-_, Ba²⁺ , 2Cl^- , H⁺, OH^-

^{step4: While balancing ions with particular charge , we have to put the magnitude of the charge as a coefficient and multiply the concentration with given mole.}

^{Therefore Mass Balance equation:}

3x 0.2 [Al³⁺] + 2x 0.1[Ba²⁺] + [H⁺] = 3x 0.2[PO₄ ^3-]​ + 2x 2 x 0.1[Cl^-] + [OH^-]

Finally Finished Charge balance equation is

0.6 [Al³⁺] + 0.2[Ba²⁺] + [H⁺] = 0.6[PO₄ ^3-]​ + 0.4[Cl^-] + [OH^-]

B) Mass Balance Equation

step 1: While writing mass balance equation we to do dissociation of salt

step 2: we should consider auto ionisation of water if it is aq.solution

We can write mass balansce euaqtion for sodium acetate as follows

CH₃COONa CH₃COO^- + Na⁺

CH₃COO^- + H₂O CH​₃COOH + OH^-

^{Therefore Mass Balance}

^[ Na^{+] = [} CH₃COO^{- ] +} [CH₃COOH ]

In Mass balance, we have to consider dissociation of sosium acetate salt and auto ionisation of water provided the salt is taken in water.