Inorganic Chemistry As

Front 1

Describe the properties of group 2 elements

Back 1

Reactivity increases down the group, melting points generally decrease down the group.

Front 2

Describe the reaction between group 2 elements and water

Back 2

Group 2 elements react with water to give a metal hydroxide and hydrogen, oxidised from a state of 0 to +2.

Front 3

Describe solubility trends of compounds of group 2 elements

Back 3

Compounds of group 2 elements that contain singly charged negative ions increase in solubility down the group, whereas compounds that contain doubly charged negative ions decrease in solubility down the group.

Front 4

What is the test for sulphate ions?

Back 4

If acidified barium chloride is added to a solution containing sulphate ions a white precipitate of barium sulphate is formed.

Front 5

Name 2 uses of group 2 element compounds.

Back 5

Calcium hydroxide is used in agriculture to neutralise acid soils and magnesium hydroxide is used in some indigestion tablets as an antacid, neutralising excess stomach acid.

Front 6

How do barium meals work?

Back 6

Barium sulphate is opaque to x-rays, so a patient swallows the barium meal and the barium sulphate coats the tissues, making them show up on an x-ray.

Front 7

How is magnesium used in the extraction of titanium?

Back 7

The main titanium ore, titanium(IV) oxide is converted to titanium(IV) chloride by heating it with carbon in a stream of chlorine gas. The titanium chloride is then purified by fractional distillation before being reduced by magnesium in a furnace at 1000 °C.

Front 8

Describe the properties of the halogens

Back 8

The boiling points increase down the group, reactivity decreases down the group and electronegativity decreases down the group.

Front 9

Describe the oxidising strengths of the halogens

Back 9

They become less oxidising down the group, so a halogen will displace a halide from the solution if the halide is below it in the periodic table.

Front 10

How is bleach made?

Back 10

If you mix chlorine gas with cold, dilute, aqueous sodium hydroxide you get sodium chlorate(I) solution, which is bleach.

Front 11

How is chlorine used to kill bacteria in water?

Back 11

When you mix chlorine with water it undergoes disproportionation, making a mixture of chloride and chlorate(I) ions, and the chlorate(I) ions kill bacteria.

Front 12

What are the risks from using chlorine to treat water?

Back 12

Chlorine gas irritates the respiratory system, and liquid chlorine on the skin causes severe chemical burns. Water contains a variety of organic compounds, and when chlorine reacts with these compounds they form chlorinated hydrocarbons which are carcinogenic.

Front 13

How does the reducing power of halide ions change down the group?

Back 13

The reducing power increases down the group because they are further away with more shielding.

Front 14

Describe the reaction between sodium fluoride or chloride with sulphuric acid

Back 14

Either hydrogen fluoride or chloride gas is formed, but HF and HCl aren't strong enough reducing agents so the reaction stops there.

Front 15

Describe the reaction between sodium bromide and sulphuric acid

Back 15

The first reaction gives hydrogen bromide gas, and this then reacts with the sulphuric acid in a redox reaction, producing sulphur dioxide, bromine gas and water.

Front 16

Describe the reaction between sodium iodide and sulphuric acid

Back 16

Hydrogen iodide is produced and this then reduces the sulphuric acid to produce sulphur dioxide, iodine and water. However it also reduces the sulphur dioxide to hydrogen sulphide.

Front 17

Describe the test for halides

Back 17

First add dilute nitric acid to remove any other ions, and then add a few drops of silver nitrate solution, and a precipitate will be formed. Iodide gives a yellow precipitate, bromide cream, chloride white and fluoride no precipitate.

Front 18

How can you make sure you have the halide ion after the silver nitrate test?

Back 18

Add ammonia solution, as the chloride precipitate dissolves in dilute solution, bromide dissolves in concentrated solution, and the iodide solution is insoluble in concentrated solution.

Front 19

Describe the test for group 2 ions

Back 19

Dip a nichrome wire loop in concentrated hydrochloric acid and then dip it into the unknown compound. Hold the loop in the clear blue part of a Bunsen burner flame and a calcium ion will show a brick red colour, strontium red and barium pale green.

Front 20

Describe the test for ammonium ions

Back 20

If you add dilute sodium hydroxide solution and gently heat the mixture then ammonia gas and water will be produced.

Front 21

What is the test for carbonates?

Back 21

Add dilute hydrochloric acid to a solution containing carbonate ions, carbon dioxide is produced, which turns limewater cloudy.