Sulfuric acid is a strong mineral acid that reacts with highly viscous Aluminium phosphate. Let us now discuss the reaction: H_{2}SO_{4} + AlPO_{4}.

**Sulfuric acid, also called oil of vitriol, is a colourless,odourless mineral acid. Concentrated H _{2}SO_{4 }is corrosive and acts as an oxidant with strong dehydrating properties. Aluminium phosphate(AlPO_{4}),occurs as a mineral berlinite, a highly viscous gel used in making ceramics, cosmetics, and paints.**

In the following article, we will discuss the type of reaction, how to balance the reaction, the ionic form of the reaction, reaction enthalpy, and various other facts about the reaction between H_{2}SO_{4} and AlPO_{4}.

## What is the product of H_{2}SO_{4} and AlPO_{4}?

**Aluminium sulfate, Al_{2}(SO_{4})_{3} and Phosphoric acid (H_{3}PO_{4})**

**are formed in reaction H**

_{2}SO_{4}+ AlPO_{4}**.**

**H _{2}SO_{4} + AlPO_{4} = Al_{2}(SO_{4})_{3 }+ H_{3}PO_{4}**

## What type of reaction is H_{2}SO_{4} + AlPO_{4}?

**The reaction H _{2}SO_{4} + AlPO_{4} is a double displacement reaction also known as Metathesis. **

## How to balance H_{2}SO_{4} + AlPO_{4}?

**The reaction between H**_{2}**SO**_{4}** and AlPO**_{4} **is- **

**H _{2}SO_{4} + AlPO_{4} = Al_{2}(SO_{4})_{3 }+ H_{3}PO_{4 }**

**To balance this equation following steps are used:**

**The reactants and the products are labeled by a, b, c, and d variables to represent the unknown coefficients.****a****H**_{2}SO_{4}+ bAlPO_{4}= cAl_{2}(SO_{4})_{3 }+ dH_{3}PO_{4}**The same type of elements is rearranged together, and then the coefficients are equated.****After rearranging by their stoichiometric proportion, we get****Al=a=2c; P=a=d; O=4a=4b=12c=4d; H=2b=3d; S=b=3c****Now we use the Gaussian elimination method to determine the values of the coefficients****We get a=3 , b=2 , c=1 , d=2****Hence the overall balanced equation is:****3H**_{2}SO_{4}+ 2AlPO_{4}= Al_{2}(SO_{4})_{3 }+ 2H_{3}PO_{4}

## H_{2}SO_{4} + AlPO_{4} titration

**The titration of H _{2}SO_{4} and AlPO_{4 }is not possible, as H_{2}SO_{4} is a strong acid whereas AlPO_{4 }is an acidic salt. Thus the determination of any particular end point is not possible.**

## H_{2}SO_{4} + AlPO_{4} net ionic equation

**The net ionic equation is –**

**2AlPO _{4}(s) = 2Al^{3+}(aq)+ 2PO_{4}^{3-}(aq)**

**The net equation is derived using the following steps –**

**Firstly the chemical states are indicated in the equation:****3H**_{2}SO_{4}(aq.) + 2AlPO_{4}(s) = Al_{2}(SO_{4})_{3}(aq.)+ 2H_{3}PO_{4}(aq.)**Then the corresponding compounds are split into their ionic forms as follows****6****H**^{+}(aq) + 3SO_{4}^{2}^{–}(aq) +**2AlPO**_{4}(s)**= 2Al**^{3+}(aq)+ 3SO_{4}^{2}^{–}(aq) + 6H^{+}(aq)+ 2PO_{4}^{3-}(aq)**The common ions on each sides cancels each other.****Thus net ionic equation is:****2AlPO**_{4}(s) = 2Al^{3+}(aq)+ 2PO_{4}^{3-}(aq)

## H_{2}SO_{4} + AlPO_{4} conjugate pairs

**The conjugate pairs of H _{2}SO_{4} and AlPO_{4 }are:**

**The conjugate base for H**_{2}SO_{4 }is HSO_{4}^{–}**The conjugate base for H**_{3}PO_{4 }is H_{2}PO_{4}^{–}

## H_{2}SO_{4} and AlPO_{4} intermolecular forces

**The intermolecular forces in H _{2}SO_{4} and AlPO_{4 }molecules are:**

**Vanderwaal forces and dipole-dipole interactions****are the intermolecular forces in H**_{2}SO_{4}.**AlPO**_{4 }is a ionic molecule and has a strong intermolecular forces of attraction i.e, dipole-dipole interaction and london forces between the aluminium cations and phosphate anions.

## H_{2}SO_{4} + AlPO_{4} reaction enthalpy

**H _{2}SO_{4} + AlPO_{4} reaction enthalpy is 200.61 KJ/mol.**

_{MOLECULE} | _{ENTHALPY (KJ/MOL)} |
---|---|

H_{2}SO_{4} | -909.27 |

AlPO_{4} | -1733.4 |

Al_{2}(SO_{4})_{3} | -3440 |

H_{3}PO_{4} | -1277 |

**Table for enthalpy**

**The formula for enthalpy calculation is =****Enthalpy of Product – Enthalpy of Reactant****= [-1277 x 2 + 1 x (-3440)] – [2 x (-1733.4) + 3 x (-909.27)]****KJ/mol****= -5994-(-6194.61)****KJ/mol****= 200.61 KJ/mol**

## Is H_{2}SO_{4} + AlPO_{4} a buffer solution?

**H _{2}SO_{4} + AlPO_{4} cannot form a buffer solution. It is because of the fact that H_{2}SO_{4 }is a strong acid which cannot form a buffer solution as buffer solutions contain weak acids.**

## Is H_{2}SO_{4} + AlPO_{4} a complete reaction?

**H _{2}SO_{4} + AlPO_{4} is a complete reaction because at the end of the reaction Al_{2}(SO_{4})_{3 }and H_{3}PO_{4 }are obtained as the products.**

## Is H_{2}SO_{4} + AlPO_{4} an exothermic or endothermic reaction?

**H _{2}SO_{4} + AlPO_{4} is an endothermic reaction since the reaction shows a positive enthalpy value of 200.61 KJ/mol.**

## Is H_{2}SO_{4} + AlPO_{4} a redox reaction?

**H _{2}SO_{4} + AlPO_{4} is not a redox reaction, as the oxidation states of the elements remain the same even after the reaction.**

## Is H_{2}SO_{4} + AlPO_{4} a precipitation reaction?

**H _{2}SO_{4} + AlPO_{4} is a precipitation reaction, because Al_{2}(SO_{4})_{3 }is obtained in the form of a white crystalline precipitate at the end of the reaction which is not soluble in H_{3}PO_{4 }.**

## Is H_{2}SO_{4} + AlPO_{4 }reversible or irreversible reaction?

**H _{2}SO_{4} + AlPO_{4 } is an irreversible reaction since the products formed in the reaction does not react back and form the reactants in the reaction.**

## Is H_{2}SO_{4} + AlPO_{4} displacement reaction?

**H _{2}SO_{4} + AlPO_{4 }is a double displacement reaction where both Al^{3+} and PO_{4}^{3-} exchanges its place with H^{+} and SO_{4}^{2-} to form entirely new products.**

#### Conclusion

Aluminium phosphate is used as a catalyst and as an ion exchanger. Sulfuric acid is used in various concentration in the manufacturing of fertilizers, pigments, dyes. The reaction between H_{2}SO_{4} and AlPO_{4 }is a metathesis reaction in which Al_{2}(SO_{4})_{3}** _{ }**and H

_{3}PO

_{4}are the products.

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.