Question

20) If you have 4.450 x 1025 individual formaldehyde (CH2O = 30.03 g/mol) molecules, and their density is 0.8150 g/mL., then how many mL of space do they occupy? ________ mL

Answer 1

2722.81 mL

Step-by-step explanation

Given:

Density = 0.8150 g/mL

Molecular mass CH2O = 30.03 g/mol

Number of formaldehyde, CH2O molecules = 4.450 x 10²⁵ moelcules

You need to first convert the number of molecules of formaldehyde to moles.

To do this, divide the the number of molecules by Avogardro's number

`4.450*10^(25)\text{ molecules }=(4.450*10^(25))/(6.022*10^(23))moles=73.89571571\text{ moles}`

Since molecular mass of 1 mole of CH2O = 30.03 g

Then, the mass of 73.89571571 moles will be

`30.03*73.89571571=2219.088343\text{ g}`

Now we can calculate the mL of space (volume) occupied by the molecules using the formula below

`\text{Volume }=(Mass)/(Density)`
`\text{Volume }=\frac{2219.088343\text{ g}}{0.8150\text{ g/mL}}=2722.81\text{ mL}`

2722.81 mL mL of space were occuppied by the formaldehyde.