Chemical Equation
A chemical
change can be represented by a
chemical equation with chemical symbols. The symbols for the
reactants are placed on the left hand side of the equation (before
the arrow) and the symbols for the products are placed on the
right hand side (after the arrow). The equation has to be balanced
in terms of the number of moles
of the reactant elements
and the number of moles
of the product elements.
In
the example of the burning of hydrogen, the
chemical equation is
The
number that is placed in front of the symbol for the element
or compound is known as the coefficient. The coefficient denotes
the number of of moles.
In the equation above, two moles
of hydrogen react with
one mole
of oxygen to produce two moles
of water. The subscript that is placed after the element
symbol shows the number of atoms for that element.
Persamaan Kimia
Suatu
perubahan
kimia
boleh diwakili oleh persamaan kimia dengan simbol-simbol
kimia. Simbol-simbol kimia reaktan ditulis pada bahagian kiri
persamaan (sebelum anak panah) dan simbol-simbol hasil /
produk kimia ditulis di bahagian kanan (selepas anak panah).
Persamaan kimia mesti diseimbangkan. Bilangan mol
unsur reaktan mesti menyimbangi bilangan mol
unsur reaktan produk.
Dalam
contoh
pembakaran hidrogen,
persamaan kimia adalah
Nombor
yang
ditulis sebelum simbol unsur
atau sebatian dikenali sebagai pekali / koefisyen. Pekali /
Koefisyen menunjukkan bilangan mol.
Dalam persamaan di atas, dua mol
hidrogen
bertindak balas dengan satu mol
oksigen
untuk menghasilkan dua mol
air. Subskrip yang ditulis selepas simbol unsur
menunjukkan bilangan atom bagi unsur tersebut.
