he molar mass of gold is 0.197kg. Calculate the mass of a gold atom, to 3 SF. (1 mole = 6x10e23)

Guest Mar 3, 2015

#1**+5 **

Just divide the mass by Avogadro's number (given in the question as 6*10^{23})

$$\frac{0.197}{6\times 10^{23}}= 0.03283\times 10^{-23}kg$$

or

$$3.28\times 10^{-25}kg$$

.

Alan
Mar 3, 2015

#2**0 **

Thanks Alan,

So is there always 6x10^23 atoms in a mole (of anything) ?

Can you (or someone else) tell us a little about the significance of Avogadro's number? (Only if is relatively easy to do. )

Melody
Mar 4, 2015

#3**+5 **

By definition a mole is Avogadro's number worth!

Avogadro's number is more precisely given by: 6.02214129×10^{23 }

Have a look at http://en.wikipedia.org/wiki/Avogadro_constant for more details.

.

Alan
Mar 4, 2015