Question

How many molecules are in $165\text{ }g$ of carbon dioxide?

Answer 1

To solve this type of questions firstly we need to calculate number of moles $C{{O}_{2}}$ of at present then we have to multiply the given number of moles by Avogadro's number for finally find out the actual numbers of moles and mole concept The mole is unit of measurement for a amount of the substance in system unit that too not standard but International System. A mole of the substance is the mole of particles which are defined as containing exactly by Avogadro's number $=6.022\times {{10}^{23}}$

Complete step-by-step answer:
Before we move forward with a solution let us discuss some important concepts of mole. A mole is a physical quantity which represents the amount of mass of the substance required to have a collective of atoms $6.022\times {{10}^{23}}$ of the given substance.

Here mole is widely used for units that calculate the amount of the matter of substance. One mole of every substance weighs about the same as molecular mass of the similar substance

We use the Avogadro's numbers of $6.022\times {{10}^{23}}$ molecule per mole to the calculate number of molecule from number of mole represented by the $165\text{ }g$of carbon dioxide compound.

The gram molecular weight of the carbon dioxide which can be calculated from its atomic weights for carbon and subsequent oxygen atom of two of them in $C{{O}_{2}}$ which is given in the periodic elements.

$\dfrac{165gC{{O}_{2}}}{44.01\dfrac{g}{mol}}\times \dfrac{6.022\times {{10}^{23}}molecules}{mol}$

$\Rightarrow 2.2589\times {{10}^{24}}molecules$

Note: Note that the mole concepts simplify mass relation among reactant and product like we can have base and our calculation on coefficient number of molecules involved in reaction. At the same time mass of substances are on a lab scale unit.