Question

How many grams of rubidium are in 2.39x10^24 atoms of rubidium?Calculate the mass (in grams) of 3.85x10^24 carbon atoms?

Answer 1

Answer:

$339.44\text{ g}$

Explanation:

Here, we want to get the mass in the given number of atoms

Firstly, we need to get the number of moles in the given number of atoms

Mathematically:

$1\text{ mole contains 6.02 }\times\text{ 10}^{23}\text{ atoms}$

The number of moles in the given number of atoms would be:

$\frac{2.39\text{ }\times\text{ 10}^{24}}{6.02\text{ }\times\text{ 10}^{23}}\text{ = 3.97 moles}$

To get the mass, we need to multiply this number of mole by the atomic mass of Rubidium

The atomic mass of rubidium is 85.5 amu

Thus, we have the mass as:

$\begin{gathered} mass\text{ = number of moles }\times\text{ atomic mass} \\ =\text{ 3.97 }\times\text{ 85.5 = 339.44 g} \end{gathered}$