Question

How many moles are there in 28 grams of $C{{O}_{2}}$?

Answer 1

Hint: Mole is generally represented by the symbol mol. It is generally described as the unit of measurement for the amount of substance in SI where SI stands for International System of units. It is defined on the basis of Avogadro’s number.

Complete answer:
A mole of a substance or particle can be defined as containing exactly $6.02214076\times {{10}^{23}}$ particles which may be atoms, molecules or ions where $6.02214076\times {{10}^{23}}$ is known as the Avogadro’s number.
Now to calculate the number of moles in 28 grams of $C{{O}_{2}}$ we first have to calculate the molecular weight of$C{{O}_{2}}$. The molecular weight of substance is defined as the weight in atomic mass units of each of the atoms in a given formula where an atomic mass unit is described as $1/12^{th}$ the weight of the carbon-12 isotope. The molecular weight of a material is required to tell an individual how many grams there are in one mole of that chemical substance i.e. molecular weight of any substance contains 1 mole of that substance.
Molecular weight of $C{{O}_{2}}$= $12+16\times 2=12+32=44$
This defines that 44 g of $C{{O}_{2}}$ contains = 1 mole of substance
Then 28 g of $C{{O}_{2}}$ contains = 0.636 moles of $C{{O}_{2}}$.
Hence we can say that there are 0.636 present in 28 g of $C{{O}_{2}}$.

Note: $C{{O}_{2}}$ is known by the name carbon dioxide which is colorless gas whose density is almost 53% higher than air it is composed of carbon and oxygen in which carbon atom are covalently double bonded with two oxygen atoms.