Question

Write down the names of compound represented by the following formulae:
$\left( a \right)$ $KN{O_3}$
$\left( b \right)$ $A{l_2}{\left( {S{O_4}} \right)_3}$
$\left( c \right)$ ${H_2}O$

Answer 1

Hint:All these given compounds are ionic in nature except ${H_2}O$ and all ionic compounds are neutral in charge hereby neutralizing the charges of the cation and anion. There are following method to write the name of ionic compound such stock method

Complete step-by-step answer:The name of the compound that is $KN{O_3}$ and $A{l_2}{\left( {S{O_4}} \right)_3}$can be written by stock method of naming. Both compounds are ionic compounds. An ionic compound is named first cation and then by its anion. The cation has the same name as its element (in this case cations are ${K^ + }$ and $A{l^{3 + }}$ they are called potassium and aluminium). The anion is named by taking the elemental name by removing the ending and adding “-ide” (for example ${F^{ - 1}}$ is called fluoride, for the element name fluorine. But if either the cation or the anion are a polyatomic ion (As in our case), the polyatomic ion name is used in the name of the overall compound. The polyatomic ion name stays the same.
The name of the $KN{O_3}$ as per above rule is Potassium nitrate and the name of the $A{l_2}{\left( {S{O_4}} \right)_3}$ is Aluminium nitrate.
${H_2}O$ is a molecular compound there are some rule for naming the molecular compounds;
Removing the ending of the second element and adding “ide” then naming molecular compounds prefixes are used to represent the number of given elements and if there are two vowel in a row that sound the same once the prefix is added, the extra vowel is removed..
Generally the more electropositive element is written first then followed by more electronegative.
As per the above rule the name of ${H_2}O$ is dihydrogen monoxide.
Name of the given compounds,
$KN{O_3}$ : Potassium nitrate
$A{l_2}{\left( {S{O_4}} \right)_2}$ : Aluminium sulphate
${H_2}O$ : Dihydrogen monoxide

Note: It is to be noted that there are two types of names that are common names and systematic names; common names of compounds are sometimes used in informal conversations between chemists, especially older chemists. Systematic names are formal names that are always used in print.