1. Introduction To Mercury, Hg.
Mercury is a chemical element with the symbol Hg. It has 80 number of Proton, and 1 mole of it
contains 201 gram of Mercury. It is located in the period 6 group 12. The electron configuration for
Mercury is [Xe] 4f145d106s2.
Figure 1 : The Electron Configuration of Mercury.
Mercury atoms have higher tendency to become a positively charge ion, cation, with an oxidation
number of +2, to achieve a stable octet electron configuration.
Hg -> Hg2+ + 2e
However in certain cases, Mercury can also release one electron due to sharing electron with
other atoms to produce another compound. For example in, Mercuric Chloride Hg2Cl. The oxidation
number of Mercury is +1.
The ionization energy pattern in Mercury
The ionization energy is the energy required to remove the most loosely held electron
from one mole of gaseous atoms to produce 1 mole of gaseous ions. The ionization energies of
mercury are given below.
Ionization energy number Enthalpy /kJ mol-1
1st 1007.1
2nd 1810
3rd 3300
Table 1: The relationship between ionization energy number with enthalpy

2. Enthalpy vs Ionization Energy Number
3500
3000
2500
2000
Enthalpy vs Ionization
1500
Energy Number
1000
500
0
1 2 3
Physical Properties of Mercury.
Mercury, which is also known as Quicksilver, has a freezing point of −38.83 °C and a boiling
point at 356.73 °C. It is clearly shows that Mercury will be in the form of liquid in standard temperature
and pressure, s.t.p. (1 atm, 1 °C) . Mercury is a heavy, silvery-white metal. As compared to other metals,
it is a poor conductor of heat, but a fair conductor of electricity.
Figure 2 : Liquid Mercury
Mercury has two physical properties of special interest. First, it has very high surface tension.
Surface tension is a property of liquids that make them act like they are covered with a skin. For

3. example, some water bugs are able to walk on the surface of water. With care, one can float a
needle on the surface of water. These incidents are possible because of water's surface tension.
Secondly, Mercury is also a very good conductor of electricity. This property is used in a number
of practical devices. One such device is a mercury switch, such as the kind that turns lights on
and off. A small amount of mercury can be placed into a tiny glass capsule. The capsule can be
made to tip back and forth. As it tips, the mercury flows from one end to the other. At one end of
the capsule, the mercury may allow an electric current to flow through a circuit. At the other end,
no mercury is present, so no current can flow. Mercury switches are easy to make and very
efficient
.
Figure 2 : Mercury Switch
The type of bond that we can found in Mercury is Metallic Bond. Usually most of the metal will
have a metallic bond. For example like Sodium (Na), Magnesium (Mg) and Aluminum (Al). But what is
Metallic bond? Why is that most metal will have these kind of bond? Precisely, Metallic Bond is the
chemical bonding that holds the atoms of a metal together. Metallic bonds are formed from the attraction
between mobile electrons and fixed, positively charged metallic atoms. Whereas most chemical bonds are
localized between specific neighboring atoms, metallic bonds extend over the entire molecular structure
Chemical Properties of Mercury.
i. Formation of Insoluble Salt.
Insoluble salt can be prepared by double decomposition method. Double decomposition method
involved the addition of one soluble salt solution with another one soluble salt.
Soluble salt + Soluble salt -> insoluble salt + soluble salt.

4. One of the insoluble salt that we can produce is Mercury (II) Chloride. This orange precipitate,
HgCl2 , is highly toxic. Firstly we need to prepare 0.5 M sodium iodide (very pale yellow) and 0.1
M mercury(II) chloride (colorless). Pour 0.1 M mercury(II) chloride (colorless) into a test tube,
followed by 0.5 M sodium iodide.
ii. Reaction of mercury with air
Mercury metal reacts in air at about 350°C to form Mercury(II) oxide.
2Hg(s) + O2(g) → 2HgO(s) [red]
iii. Reaction of mercury with water
Mercury does not react with water under normal conditions.
Hg + H2O → no observable changes.
iv. Reaction of mercury with the halogens
Mercury metal reacts with fluorine, F2, chlorine, Cl2, bromine, Br2, or iodine, I2, to form the
dihalides mercury(II) fluoride, HgF2, mercury(II) chloride, HgCl2, mercury(II) bromide, HgBr2,
or mercury(II) iodide, HgI2, respectively.
Hg(l) + F2(g) → HgF2(s) [white]
Hg(l) + Cl2(g) → HgCl2(s) [white]
Hg(l) + Br2(l) → HgBr2(s) [white]
Hg(l) + I2(s) → HgI2(s) [red]
v. Reaction of mercury with acids
Mercury does not react with non-oxidizing acids but does react with concentrated nitric acid,
HNO3, or concentrated sulphuric acid, H2SO4, to form mercury(II) compounds together with
nitrogen or sulphur oxides.
Mercury dissolves slowly in dilute nitric acid to form mercury(I) nitrate, mercurous nitrate,
Hg2(NO3)2.
vi.Organic mercury: Mercury can also combine with organic groups such as methyl
groups to form organic mercury. The most common compound of this type is methyl
mercury, which is somewhat soluble in water, bio-available and highly toxic.

5. Bibliography
1. Chemistry, Nexus SPM A+, Toh Kim Kau, Sasbadi Sdn. Bhd. ( Chapter 4, Periodic Table of
Elements )
2. http://www.webelements.com/mercury/chemistry.html
3. http://www.webelements.com/mercury/atoms.html
4. http://www.chemistryexplained.com/elements/L-P/Mercury.html
5. http://www.chemguide.co.uk/atoms/properties/ies.html