Question

2. Calculate the mass of 3.47x1023 gold atoms.

Answer 1

3.47 x $10^{23}$ atoms of gold have mass of 113.44 grams.

Explanation:

Data given:

number of atoms of gold = 3.47 x $10^{23}$

mass of the gold in given number of atoms = ?

atomic mass of gold =196.96 grams/mole

Avagadro's number = 6.022 X $10^{23}$

from the relation,

1 mole of element contains 6.022 x $10^{23}$ atoms.

so no of moles of gold given = $\frac{3.47 X 10^{23} }{6.022 X 10^{23} }$

0.57 moles of gold.

from the relation:

number of moles = $\frac{mass}{atomic mass of 1 mole}$

rearranging the equation,

mass = number of moles x atomic mass

mass = 0.57 x 196.96

mass = 113.44 grams

thus, 3.47 x $10^{23}$ atoms of gold have mass of 113.44 grams