Question

Write the chemical formula of the following
a) Magnesium chloride
b) Calcium oxide
c) Copper nitrate
d) Aluminium chloride
e) Calcium carbonate

Answer 1

Hint: The chemical formula of a compound is a symbolic representation of its chemical composition. Moreover, the chemical formula provides an insight into the elements that constitute the molecules of a compound and also the ratio in which the atoms of these elements combine.

Complete answer:
A chemical formula is defined as a collection of chemical symbols that is used to show the elements present in any compound and its proportion. For example: The chemical formula of water is $H_{2}O$ . It says that two hydrogen atoms combine with one oxygen atom to form one molecule of water.

Now let’s write the chemical formula of the given compounds.
a) We have been given the compound magnesium chloride.
There are two ions present in it. The valence of the ions corresponding to magnesium and chloride is two and one respectively. So cross multiplying it we get the formula as $MgC{l}_2$
b) Now we have been the given the compound calcium oxide
There are two ions present in it. The valence of the ions corresponding to calcium and oxide is two and two respectively. So cross multiplying it we get the formula as $CaO$.
c) Now we have been the given the compound copper nitrate
There are two ions present in it. The valence of the ions corresponding to copper and nitrate is two and one respectively. So cross multiplying it we get the formula as $Cu{(N{O}_3)}_2$
d) Now we have been the given the compound aluminium chloride
There are two ions present in it. The valence of the ions corresponding to aluminium and chloride is three and one respectively. So cross multiplying it we get the formula as $AlC{l}_3$
e) Now we have been the given the compound calcium carbonate
There are two ions present in it. The valence of the ions corresponding to calcium and carbonate is two and two respectively. So cross multiplying it we get the formula as $CaC{O}_3$

Note: The empirical formula of a compound represents the ratio of the elements present in the compound. It is usually obtained by the analysis of experimental data. For example, the empirical formula of glucose is and it can further be derived by the molecular formula.