Question

How many molecules are in 165 g of carbon dioxide?

Answer 1

The molar mass of CO2 is 44 grams per mole.

165 grams / 44 grams per mole of CO2 = 3.75 moles CO2

Using Avogadro’s law where 1 mole of substance equals 6.023 x 10^23 molecules

3.75 moles CO2 (6.023 x 10^23 molecules /mole) = 2.26 x 10^24 molecules CO2

Answer 2

Answer: $22.6 \times 10^{23}$ molecules

Explanation:

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$  

For $CO_2$

Given mass= 165 g

Molar mass of  $CO_2$ = 44 g/mol

Putting values in above equation, we get:

$\text{Moles of}CO_2 =\frac{165g}{44g/mol}=3.75mol$

According to avogadro's law, 1 mole of every substance weighs equal to the molecular mass and contains avogadro's number $6.023\times 10^{23}$ of particles.

1 mole of $CO_2$ contains =$6.023\times 10^{23}$ molecules of   $CO_2$

Thus 3.75 moles $CO_2$ contains =$\frac{6.023\times 10^{23}}{1}\times 3.75=22.6 \times 10^{23}$ molecules of $CO_2$

Thus there will be $22.6 \times 10^{23}$ molecules of $CO_2$