Question

How many moles are in $75.0g$ of dinitrogen trioxide ${N_2}{O_3}$ ?

Answer 1

To find the moles in a given compound firstly find the mass(in grams) of compound in given question , then calculate the molar mass of that compound .After finding the molar mass of compound divide the given mass of compound by molar mass of that compound you will get no of moles.

Complete step by step answer:
Molar mass: The mass of a given substance (chemical component or compound) partitioned by its measure of substance (mol), in$g/mol$ .
Mole: The measure of substance that contains the same number of elementary elements as there are atoms in $12{\text{ }}g$ of $carbon - 12$ .
Step1) find the number of grams is given in the problem.
Given, $75.0g$ of dinitrogen trioxide ${N_2}{O_3}$
Step2) Determine the molar mass of the substance.
Molar mass of ${N_2}{O_3}$=$2{\text{ }}\times{\text{ }}14.007\,$ $+ {\text{ }}15.999{\text{ }}\times3$ $= 76.01{\text{ }}g/mol$
Step3) Divide the given mass of substance in grams by its molar mass
Thus, we get:
n$$${N_2}$ ${O_3}$ = $\dfrac{{75g}}{{76.01g/mol}}$ =0.987{\text{ }}mo{l_{}} Step4) If this problem were set up like the proportion above, you would have this: $\dfrac{{75g}}{n}$ =$\dfrac{{76.01g/mol}}{{1mol}}$ Step5) Cross-multiply and divide to solve for the unknown 75g{\text{ }}\times{\text{ }}1mol{\text{ }} = {\text{ }}76.01{\text{ }}g/mol{\text{ }}\times{\text{ }}n$$n = {\text{ }}0.987{\text{ }}mol$$

Note:
The molar mass of a compound is equivalent to the amount of the atomic masses of its constituent atoms in $g/mol$ .
Despite the fact that there is no physical way of measuring the number of moles of a compound, we can relate its mass to the number of moles by utilizing the compound's molar mass as a direct conversion factor.
To change over among mass and number of moles, you can use the molar mass of the substance. At that point, you can use Avogadro's number to convert the number of moles over to the number of atoms