Question

For the following pair of elements, deduce the formula and name.

Lithium and oxygen

Accepted Answer

A chemical formula represents the proportions, by mass of the different elements in a compound.

A binary compound is composed of two different elements only. Formulae of binary compounds can be written using valencies since both types of atom forming the compound must lose, gain or share the same number of electrons. To write the chemical formula of a binary compound ;

Determine the valency of the both elements present.

Write the chemical formula such that the sums of the valencies of the two elements are equal. Do this by determining the lowest common multiple of the two valencies.

If a metal is present, always place it first in the formula.

For naming, The first component in the formula is simply identified with the element name. The second component is named by taking the name of the element stem and adding the -ide suffix. The number of atoms in a molecule is determined using a scheme of numerical prefixes.

$\Rightarrow$ Lithium and oxygen

Valencies of elements:

$Li = 1$ (Group I)

$O = 2$ (Group VI)

The lowest common multiple of valencies $= 2$

$Li = 1 \times 2 = 2$

$O = 2 \times 1 = 2$

Therefore, the chemical formula $= {Li}_{2} O$ and name is Lithium oxide.

Gary Horner Solutions for Chapter: Models, Exercise 10: Exercise 10

Gary Horner Chemistry Solutions for Exercise - Gary Horner Solutions for Chapter: Models, Exercise 10: Exercise 10

Questions from Gary Horner Solutions for Chapter: Models, Exercise 10: Exercise 10 with Hints & Solutions

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