Question

How many acetone molecules are in a bottle of acetone with a volume of 445 mL ? (density of acetone = 0.788 g/cm3).

Answer 1

Hello!

The answer is: $3.63x10^{24}particles$

Why?

First, we need to calculate the molecular weight of the acetone (CH3COCH3)

So,

$C=12.011g/mol\\O=15.99g/mol\\H=1.008g/mol$

Then,

$CH3COCH3=12.011+(1.008)*3+12.011+15.999+12.011+(1.008)*3=58.08g/mol$

Second, we need to calculate the mass of the acetone in the bottle

We need to remember that $1cm^{3}=1mL$

So,

$445cm^{3}*\frac{0.788g}{cm^{3}}=350.66g$

Third, we need to calculate the number of moles:

$350.66g*\frac{1mol}{58.08g}=6.03moles$

Fourth, we need to calculate the number of atoms:

Remember, $1 mol=6.022x10^{23}particles$

Therefore,

$6.03moles*\frac{6.022x10^{23}particles }{1mol}=3.63x10^{24}particles$

Have a nice day!

Answer 2

Answer:

The number of molecules would be 2.5*10^24 molecules

Explanation:

In order to find the molecules, first you need the molecular formula and weight of acetone, CH3COCH3 which is 58 g/ mole.  

Let us determine mass of acetone

300mL= 300cm^3*.788g/cm^3= 236.4 g  

Finding  number of moles  

236.4g/ 58g/mol=4.08 moles  

Now the number of molecules.

4.08moles *6.02*10^23 molecules/ mole

which are 2.5*10^24 molecules