Question

calculate he number of gold in 1gram of gold (at masses of Au=197u)​

Answer 1

Answer:

Explanation:

n = Given mass/Atomic mass = 1/197

Therefore, number of gold in 1gram gold= 1/197 x (NA)

                                                                       = 1/197 x 6.023 x 10^23

                                                                       = 0.70319289 m

Answer 2

Answer:

The number of gold in 1 gram of gold is 3.057 × $10^{21}$

Explanation:

The atomic mass(M) of gold = 197 u

That is 1 mole of gold is equal to 197 g/mol

Given the mass(m) of gold = 1 g

The number of moles(n) =  Given mass(m) ÷ Atomic mass(M)

$n =\frac{m}{M} = \frac{1}{197}$ = $5.076$ × $10^{-3}$ moles

one mole of the atom contains an Avagadro number of atoms.

Therefore, $5.076$ × $10^{-3}$ moles multiplied by the Avagadro number gives the total number of gold atoms.

The number of gold atoms =  $5.076$ × $10^{-3}$ × Avogadro number

                                  =( $5.076$ × $10^{-3}$) × ($6.023$ × $10^{23}$)

                                  = 3.057 × $10^{21}$