Video Transcript
Molecules of sulfuric acid consist
of two hydrogen atoms and four atoms of oxygen. Each oxygen atom is attached to a
central sulfur atom. What is the chemical formula of
sulfuric acid?
A chemical formula is an expression
of chemical symbols and numerical subscripts that represents the composition of a
molecule or one unit of a compound. H2O is an example of a chemical
formula. Capital H is the chemical symbol of
hydrogen, and capital O is the chemical symbol of oxygen, as found on the periodic
table. The number two is a numerical
subscript. It tells us how many atoms of
hydrogen are in one molecule of H2O. When no numerical subscript is
written, only one atom of the element is present in the molecule.
Now that we understand the basics
of a chemical formula, we can look at the molecule of sulfuric acid given. We are told that the molecule
contains hydrogen, oxygen, and sulfur. We can look at the periodic table
to find the chemical symbol of each of these elements. The question tells us that a
molecule of sulfuric acid contains two hydrogen atoms, four oxygen atoms, and a
central sulfur atom.
We now have all of the information
we need to write the chemical formula. The molecule contains two atoms of
hydrogen. So, we write the chemical symbol of
hydrogen followed by a subscript two. The molecule contains one atom of
sulfur. So, we write the chemical symbol of
sulfur followed by the subscript one. However, subscript values of one
are typically not written. So, we can remove this
subscript. Finally, the molecule contains four
atoms of oxygen. So, we write the chemical symbol of
oxygen followed by a subscript four.
We now know that the chemical
formula of sulfuric acid is H2SO4.
