Magnesium oxide is another simple basic oxide, which also contains oxide ions. However, it is not as strongly basic as sodium oxide because the oxide ions are not as weakly-bound. Because of the higher charge on the metal, more energy is required to break this association. Even considering other factors such as the energy released from ion-dipole interactions between the cations and water , the net effect is that reactions involving magnesium oxide will always be less exothermic than those of sodium oxide.
Reaction with water: At first glance, magnesium oxide powder does not appear to react with water. However, the pH of the resulting solution is about 9, indicating that hydroxide ions have been produced. In fact, s ome magnesium hydroxide is formed in the reaction, but as the species is almost insoluble, few hydroxide ions actually dissolve. The reaction is shown below:. Reaction with acids: Magnesium oxide reacts with acids as predicted for a simple metal oxide. For example, it reacts with warm dilute hydrochloric acid to give magnesium chloride solution.
Describing the properties of aluminum oxide can be confusing because it exists in a number of different forms. One of those forms is very unreactive known chemically as alpha-Al 2 O 3 and is produced at high temperatures. The following reactions concern the more reactive forms of the molecule. Aluminium oxide is amphoteric. It has reactions as both a base and an acid. Reaction with water: Aluminum oxide is insoluble in water and does not react like sodium oxide and magnesium oxide. The oxide ions are held too strongly in the solid lattice to react with the water.
Reaction with acids: Aluminum oxide contains oxide ions, and thus reacts with acids in the same way sodium or magnesium oxides do. Aluminum oxide reacts with hot dilute hydrochloric acid to give aluminum chloride solution. Reaction with bases: Aluminum oxide also displays acidic properties, as shown in its reactions with bases such as sodium hydroxide. Various aluminates compounds in which the aluminum is a component in a negative ion exist, which is possible because aluminum can form covalent bonds with oxygen.
This is possible because the electronegativity difference between aluminum and oxygen is small, unlike the difference between sodium and oxygen, for example electronegativity increases across a period. Aluminum oxide reacts with hot, concentrated sodium hydroxide solution to produce a colorless solution of sodium tetrahydroxoaluminate:.
Silicon is too similar in electronegativity to oxygen to form ionic bonds. Therefore, because silicon dioxide does not contain oxide ions, it has no basic properties. In fact, it is very weakly acidic, reacting with strong bases. Reaction with water: Silicon dioxide does not react with water, due to the thermodynamic difficulty of breaking up its network covalent structure. Reaction with bases : Silicon dioxide reacts with hot, concentrated sodium hydroxide solution, forming a colorless solution of sodium silicate:.
In another example of acidic silicon dioxide reacting with a base, the Blast Furnace extraction of iron, calcium oxide from limestone reacts with silicon dioxide to produce a liquid slag, calcium silicate:.
Phosphorus III oxide: Phosphorus III oxide reacts with cold water to produce a solution of the weak acid, H 3 PO 3 —known as phosphorous acid, orthophosphorous acid or phosphonic acid:. The protons remain associated until water is added; even then, because phosphorous acid is a weak acid, few acid molecules are deprotonated. Phosphorous acid has a pK a of 2.
Phosphorus III oxide is unlikely to be reacted directly with a base. Escobar , J. Cuevas , C. Barrera , A. Effect of Rare-Earth Content. Topics in Catalysis , 63 , Pair your accounts. Your Mendeley pairing has expired.
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You know, start with the simpler cases. Then look for reactions that show how Al oxide can do both. Add a comment. Active Oldest Votes. This is indeed the case, as stated here for indium hydroxide since hydroxides are simply hydrated forms of their oxides, we can expect a similar nature for indium oxide as well : The result indicated conclusively that In OH 3 is only slightly amphoteric, being much more basic than acidic.
Before wrapping up the answer, I would like to re-iterate a point I made at the beginning of the answer: All these pathways are simply possible mechanisms, and there is no way of knowing whether they are completely correct or not without performing experiments.
Improve this answer. Yusuf Hasan Yusuf Hasan 2, 1 1 gold badge 14 14 silver badges 30 30 bronze badges. Yet in your explanations, you invoked a bridged structure for the ionic solid? From which source did you find aluminium oxide to exists as covalent molecules with a bridged structure? Maurice Maurice Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown.
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