• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Discuss - Metal oxides are alkaline, non-metal oxides are acidic

Extracts from this document...

Introduction

Discuss - Metal oxides are alkaline, non-metal oxides are acidic Moving across the periodic table from left to right will bring about a change in the nature of the element. Generally, there are trends in certain properties in the elements that we can spot, for instance boiling/melting points. Period three elements are from Sodium to Argon inclusive, and possess particular characteristics. All of the period 3 elements except argon and chlorine will combine with oxygen to form oxide molecules (Na2O, MgO, Al2O3, SiO2, P4O10, SO2 and SO3). How does their pH differ, and what is different about Al2O3? It is not just the properties of the period 3 elements that differ as we move across the periodic table; this movement also affects the properties of the oxides of said elements. These changes are a result of the transition from metal elements to non-metal elements. The oxides of sodium, magnesium and aluminium are all examples of the compounds formed by a metal combined to a non-metal. ...read more.

Middle

acid. This ionises, so the solution is acidic. P4O10 (s) + 6H2O (l) --> 4H3PO4 The H3PO4 (aq) ionises in stages, the first being: H3PO4 H+ (aq) + H2PO4- (aq) pH ~0-1 Sulphur dioxide is also fairly soluble in water, and reacts with it to give sulphuric acid. This partially dissociates producing H+ ions. This causes the acidity in the solution. SO2 (g) + H2O (l) --> H2SO3 (aq) H2SO3 (aq) H+ (aq) + HSO3- (aq) pH ~ 2-3 Sulphur trioxide reacts violently with water to produce sulphuric acid: SO3 (g) + H2O (l) --> H2SO4 (aq) --> H+ (aq) + HSO4- (aq) pH ~0-1 This overall pattern in reactivity of the period 3 oxides is that metal oxides will form alkaline solutions win water, whilst non-metal oxides will form acidic ones and those in the middle will not react. This behaviour can be explained by looking at the bonding and structure: * Sodium and magnesium oxides are composed of ions. ...read more.

Conclusion

--> Na2SiO3 (aq) + H2O (l) Due to the giant covalent lattice, silicon dioxide is very resistant to attack from bases. It will only react with a base given the conditions are right, using hot, concentrated hydroxide solution. SiO2 (s) + 2 OH - (aq) ? SiO3 2 - (aq) + H2O (l) Some of these reactions can be problematic. For instance, sulphur trioxide causes problems when reacting with water as it forms sulphuric acid (see above for equation). Were the SO3 to mix with rain water, it would form acid rain. This provides a number of environmental problems, such as, changing the pH of lakes and harming aquatic life, killing crops by changing pH of soil and ruining limestone buildings. I would mostly agree with the statement "Metal oxides are alkaline, non-metal oxides are acidic". Within period 3, the metal oxides react as an alkali whilst the non-metal oxides react as acidic. The only exception to this rule is aluminium oxide, which can act as both an acid and alkali depending on the conditions and the reactant and is referred to as amphoteric. Excluding this exception, the statement proves correct. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Physical Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Physical Chemistry essays

  1. Peer reviewed

    The Development of the Periodic Table of the Elements

    4 star(s)

    This was incredibly intuitive and meant that he could predict undiscovered elements and their properties. Furthermore, when some elements seemed out of place when arranged in ascending atomic weight, he rearranged them based on what their properties indicated - a bold move.

  2. Investigating the Rate of the Reaction between Bromide and Bromate Ions in Acid Solution

    330K), I will increase the intended temperature by 8 degrees in each experiment. Having chosen a set of concentrations, this is the method that I will use: 1. Put on safety goggles 2. Measure out the correct volumes of reactants given by the chosen concentrations (set chosen from table 2.4.1, table 2.4.2 or table 2.4.3)

  1. Investigating the rate of reaction between peroxydisulphate(VI) ions and iodide ions

    my hands before leaving the lab, wearing appropriate clothing and removing all jewellery, disposing of chemicals in a designated place and not returning unused chemicals to their original containers, to prevents contamination. In this investigation, many substances are irritant to the skin and eyes.

  2. Outline and examine some uses of different metals through history, including contemporary uses, as ...

    Molecular formula of a covalent molecular compound represents the actual number of atoms of each element present in the molecule. 1. Define terms mineral and ore with reference to economic and non-economic deposits of natural resources A mineral is a pure crystalline compound that occurs in the earth?s crust.

  1. Atomic Structure, Bonding and the Periodic Table. Revision questions.

    What type of bonding is present in potassium fluoride? Draw diagrams to show the electron arrangements of the atoms. Also draw a diagram to show how the atoms are arranged in 3D. Potassium fluoride is formed by ionic bonds.

  2. Purification of aluminium from Bauxite

    Iron rusts in damp air, dissolve in dilute acid. The uses of the final product Iron is mostly used to produce steel but is mostly used to manufacture many different parts of a car. Some types of steel are used to make materials such as cutting knife, drilling tools etc.

  1. The properties of transition metals

    The transition elements readily form alloys with themselves and with other elements. The atomic size is constant since the electrons in the outer most shells have similar environments. The low ionization potentials mean that the elements show variable valency states by loss of electrons from the s and 3d orbital.

  2. Acids and Bases in the World - acid rain, chlorine in pools and cleaning ...

    Rinsing after will remove any residue and the remaining vinegar C 1. Sulphuric acid (H2SO4) is a very strong acid, and also a very strong oxidising agent 2. Because of these properties and its high level of corrosiveness it is very efficient at cleaning drains 3.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work