Question

What is the mass of 2.234 x 10²³ (2.234E23) atoms of sulfur? (S = 32.07 g)
Round to the nearest tenth (1 decimal places)

Answer 1

The amount in moles of the sulfur sample could be determined via the following:

$n(S)=\frac{N_{atoms}}{N_{A}};$

On the other hand, the amount in moles could be determined via the following:

$n(S)=\frac{m_{S}}{M_{S}};$

After combining of the both expressions:

$\frac{m_{S}}{M_{S}}=\frac{N_{atoms}}{N_{A}},$

or

$m_{S}=\frac{N*M_{S}}{N_{S}}=\frac{2.234*10^{23}*32.07g/mol}{6.022*10^{23}mol^{-1}}=11.90g \sim 11.9g.$