|Table of contents
|Reaction of Metals with Solutions of Other Metal Salts
|The Reactivity Series
|How do Metals and Non-Metals React?
|Properties of Ionic Substances
|Occurrence of Metals
Reactive metals can displace less reactive metals from their compounds in solutions or molten form.
Aim: Experiment to compare the reactivity of metals.
Materials required: Iron nail, copper wire, copper sulphate solution, iron sulphate solution, two test tubes, test tube stand, corks, thread.
The reactivity series is a lineup of metals organized in descending order of their activity levels. Following displacement experiments, a reactivity series, also referred to as an activity series, has been established and is presented below.
Activity Series: Relative reactivities of metals
Before we discuss the reaction between metals and non-metals, let us look at the electronic configuration of some noble gases, metals and non-metals as given in the table.
Electronic Configurations of Some Elements
Formation of sodium chloride can be represented as under:
The transfer of electron from sodium to chlorine can be represented as under:
Sodium and chloride ions being oppositely charged attract each other and are held by strong electrostatic forces of attraction.
Formation of magnesium chloride can be represented as under:
Ionic substances possess the following properties:
Aim: Experiment to prove that salts impart colour to the flame.
Materials required: Burner, spatula, sodium chloride, potassium chloride and barium chloride.
Again repeat the experiment by taking barium chloride salt on a clean spatula. We observe a green flame this time.
We observe that a golden-yellow flame is produced.
Thus, many salts produce flame when ignited with a flame. We also observed that none of the salts melted during heating proving that ionic salts have high melting and boiling points.
Aim: Experiment to prove that salt solutions conduct electricity.
Materials required: A beaker, battery, bulb, switch, graphite rods, sodium chloride solution.
Elements or compounds which occur naturally in the earth’s crust are known as minerals. Minerals from which metals can be extracted profitably are called ores. Seawater also contains some soluble salts such as sodium chloride, magnesium chloride, etc.
On the basis of reactivity, we can group the metals into three categories :
(i) Metals of low reactivity. For example, gold, silver, platinum and copper.
(ii) Metals of medium reactivity. For example, zinc, iron, lead, etc.
(iii) Metals of high reactivity. For example, potassium, sodium, calcium, magnesium and aluminium.
The metal oxides are then subjected to reduction with carbon.
Aluminium is obtained by electrolytic reduction of aluminium oxide.
Aim: Perform an experiment to find out conditions which cause rusting of iron.
Materials required: Three test tubes with corks, iron nails, anhydrous calcium chloride, oil.
It is observed that iron nails rust in test tube A but they do not rust in test tubes B and C. This is because iron nails are exposed to both water and air in test tube A. In test tube B, the nails are exposed to only water and in test tube C, the nails are exposed to only air. This means presence of both water and air necessary for rusting to take place.
Rusting of iron can be prevented by the following methods:
It is a method of protecting steel and iron from rusting. The article is coated with a thin layer of zinc. The galvanised article is protected against rusting even if zinc coating is broken.
It is a method of improving the properties of a metal. If iron is mixed with a small amount of carbon (about 0.05 %), it becomes hard and strong.
|1. How do metals react with solutions of other metal salts?
|2. What is the reactivity series of metals?
|3. How do metals and non-metals react with each other?
|4. What are the properties of ionic substances?
|5. How do metals occur in nature?