Jump to content

Recommended Posts

Posted (edited)

The full question is: "What is the mass of 9.01 x 103 mole carbon tetrafluroide, CF4(g)?"

Any help on explaining how to get the answer to this is much appreciated.

Do you know what a mole is? See if you can work the problem out with this definition of a mole:

 

 

The mole is the unit for amount of substance. The molar mass is the relative formula mass of a substance in grams (measured in g/mol).

Edited by StringJunky
Posted (edited)

You need to find out the molar mass of the compound, which is in grams, and multiply that by the number of moles given. You then multiply that result with the left side of the sum. The molar mass is the combined atomic mass, expressed directly in grams, of each element in a compound.

Edited by StringJunky
Posted (edited)

You need to find out the molar mass of the compound, which is in grams, and multiply that by the number of moles given.

 

Molar mass is in [math]\frac{g}{mol}[/math] units.

 

After multiplication by moles, you get simple grams, because mol^-1 (denominator in g/mol) and mol cancel each other.

[math]\frac{g}{mol} * mol = g[/math]

 

The molar mass is the combined atomic mass, expressed directly in grams, of each element in a compound.

Atomic mass is in a.m.u (mass atomic unit), shortcut u. It's approximately 1.66*10^-27 kg.

After multiplication by 1000 (to get grams) and multiplication it by Na (Avogadro constant), you get g/mol.

Which is very large number of atoms or molecules (6.022141*10^23).

 

f.e. 12 u * 1.66*10^-27 kg/u * 1000 g/kg * 6.022141*10^23 mol^-1 = 12 g/mol

Edited by Sensei

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.