Somewhere around 27-28 I believe
The Halogen that is most likely easy to be oxidised would be the Iodine. In addition, the property that makes the Iodine ideal for oxidation is due to the fact that its d-orbital contains more electrons compared to other halogens such as fluorine where oxidation would tend to be difficult to occur on the element.
Na₃PO₄(aq)+AlBr₃(aq)→3NaBr(aq)+AlPO₄(s)
This is a double replacement reaction. You can tell that there has to be 3NaBr molecules since there are 3 Na atoms in sodium phosphate and 3 Br atoms in aluminum bromide. We also know that Na has an oxidation number of +1 which means PO₄ needs to have an oxidation number of -3 while Br has an oxidation number of -1 which means Al has an oxidation number of +3. That means that Al³⁺ and PO₄³⁻ can from AlPO₄
I hope this helps. Let me know if anything is unclear.
Ionic bond is the bond that creates a crystalline structure
An Exothermic reaction releases energy into the surroundings and so the products have more potential energy then the reactants. The enthalpy change is a negative value. Whereas, an endothermic reaction involves the absorption of energy into the system and so the reactants have more potential energy than the products. The enthalpy change is a positive value. This is clearly represented in energy profile diagrams.
