Chemical Properties of Metals and Non-metals

Every metal and non-metal has different physical and chemical properties which distinguish them from each other. Our daily activities have a close relationship with these chemical properties of the metals and non-metals to understand deeply how they will react when combined with different things. In this article, we will study various chemical reactions of these metals and non-metals with oxygen, water, acids and bases to study their chemical property.

Metals

The elements which are hard, lustrous, malleable, ductile, sonorous and good conductor of heat and electricity are called metals. For example – Iron, Copper, Aluminium, Silver and Gold etc. The most abundant metal in the Earth’s crust is aluminium. All metals are solid except Mercury. Metals are the electropositive elements that’s why they donate electrons and form positive ions to get stable.

Chemical Properties of Metals

Reaction with Oxygen

Most metals react with oxygen to form metal oxide. Generally, metal oxides are basic in nature but some metal oxides such as aluminium oxide, zinc oxide shows both acidic and basic behavior, such metal oxides which react with both acids as well as bases to produce salt and water are called Amphoteric oxides.

Metal + Oxygen = Metal oxide

Magnesium + Oxygen = Magnesium oxide

Copper + Oxygen = Copper oxide

Different metal shows different reactivities towards oxygen

1. Sodium and potassium react so vigorously that they catch fire if kept open that’s why they are kept immersed in kerosene oil to avoid accidental fires.
2. Copper does not burn but coated with black copper oxide.
3. Gold(Au) and silver(Ag) does not react with oxygen even at high temperature.
4. At room temperature, the surface of metals such as Mg, Al, Zn, Pb etc. is covered with a thin layer of oxide to prevent further oxidation.

Reaction with Water

Metals react with water to form a metal oxide or metal hydroxide and hydrogen. Metals react with water and produce a metal oxide and hydrogen gas. Metal oxides that are soluble in water dissolve in them to further form metal hydroxides.

Water = metal oxide or metal Hydroxide + hydrogen

Sodium + water = Sodium Hydroxide + hydrogen

Iron + steam =iron oxide + hydrogen

Note- Sodium reacts vigorously with water while some other metals do not do so like Iron which reacts slowly with water.

1- For Na & K, the reaction is violent even with cold water and so exothermic that hydrogen immediately catches fire when a small piece of Na or K of wheat grain size is dropped in water, it floats on the surface of the water the metal moves over the surface of the water with a hissing noise, producing tiny bubbles of hydrogen gas. Gradually becomes small in size and catches fire the solution gets hot. When tested it shows red litmus paper blue which means it is a basic solution.

2Na+2H₂O= 2NaOH+H₂+heat

2K+2H₂O=2KOH+H₂+heat

Note: Do not touch Na or K with bare hands it causes severe burns.

2- For Calcium, the reaction is less violent. When Ca metal is dropped in the water at room temperature, the following are the observations-

• It sinks in water.
• Reacts with water and produces bubbles of hydrogen gas.
• Makes the solution milky
• The water becomes hot red litmus turns blue.
• Ca+H₂O=Ca(OH)₂

3. Mg reacts with steam, it gives white color on heating.

• Mg +H₂0 = MgO+H₂(gas)

4. Zinc and Iron reacts slowly with steam.

5. Metals like Cu, Ni, Ag, Au, Pt do not react with water or steam because they are least reactive.

Reaction with Acid

Metals react with acid and produce hydrogen gas that burns with a Pop sound

Metal + Acid = metal salt + hydrogen

Sodium + HCL acid = sodium chloride + hydrogen

Zinc + Hydrochloric acid = zinc chloride + hydrogen

Reaction with Base

Metal react with base salt to form hydrogen gas

Metal + base = hydrogen gas

Zinc + Sodium Hydroxide = sodium zincate + hydrogen

Tin + sodium Hydroxide = sodium + hydralaxite + hydrogen

Summary

1. Metal reacts with oxygen to form metal oxide.
2. Metal reacts with acid to form a salt.
3. Metals react with water to form oxides or hydroxides.
4. Metals do not react with alkalis.
5. Alkalis are bases that readily dissolves in water.

Non-metals

Nonmetals are those elements that do not conduct heat and electricity and are neither malleable nor ductile. Non-metals are non-lustrous, brittle and insulator. For example – carbon, oxygen, phosphorus etc.

Out of 22 non-metals, 10 nonmetals are solid and 1 non-metal which is Bromine is a liquid. However, the remaining 11 non-metals are gases. Non-metals are the elements that form negative ions by gaining electrons. Nonmetals are electronegative. Hydrogen is only non-metal which loses electrons.

The change of one type of material into another type is a chemical property. It is any material property that comes during or after a chemical reaction. A change in which one or more new substances are formed is called a chemical change. A chemical change is also called a chemical reaction.

Chemical Properties of Non-Metals

Reaction with Oxygen

Non-metals react with oxygen to form acidic or neutral oxide.

For example- Sulphur burns in air to give sulfur dioxide

Sulphur + oxygen = Sulfur dioxide

Sulfur dioxide dissolves in water to form an acid called sulphurous acid

sulfur dioxide + water = sulfuric acid

Reaction with Water

Non-metals do not react with water though they may be very reactive in the air such non-metals are stored in water.

For example- Phosphorus is a very reactive non-metal, it catches fire if exposed to air therefore it is stored in water.

Reaction with Acid

Non-metals do not react with dilute acids and therefore hydrogen gas is not liberated.

Reaction with Base

Reaction of nonmetals with bases is quite complex they react with bases to form the salt. 

For example – 

calcium hydroxide + chlorine = bleaching powder

Sample Questions

Question 1: Why copper cannot displace zinc from its salt solution?

Answer:

Copper is less reactive than zinc, That’s why it cannot displace zinc from its solution.

Question 2: Why sodium and potassium are stored in kerosene?

Answer:

Since, they are very reactive, they readily react with air and water, that’s why stored in kerosene.

Question 3: Can you store the lemon pickle in an aluminium utensil?

Answer:

No, we cannot because aluminium is a metal and lemon contains acid. The acid reacts with metal to give hydrogen and salt. This salt is toxic in nature which will spoil the food and makes it unfit to use.

Question 4: What happens when dilute sulphuric acid is poured on a copper plate?

Answer:

Copper does not react with dilute sulphuric acid, so no reaction will take place.

Question 5: What is displacement reaction?

Answer:

The reaction in which an element replaces the element of a compound is known as displacement reaction.

Question 6: Name one non-metal and one metal, which are in the liquid state at room temperature.

Answer:

Non-metal- Bromine

Metal- Mercury

Question 7: What happens when Iron is corroded?

Answer:

When iron gets corroded, rust gets formed on its surface known as hydrated iron.