Question

The visible universe is estimated to contain ${10}^{22}$stars. How many moles are present in the visible universe?

Answer 1

Step 1: Given information

• The number of particles given $={10}^{22}$stars.
• Avogadro number $=6.022\times {10}^{23}$
• A mole is defined as an amount in which that contains as many particles as there are atoms in $12$grams of carbon$-12$.

Step 2: Finding the number of moles present in the universe

• 1 mole of star $=6.022\times {10}^{23}$
• We know, the number of moles $\left(\mathrm{n}\right)=\frac{\mathrm{Number}\mathrm{of}\mathrm{particles}\mathrm{given}\left(\mathrm{N}\right)}{\mathrm{Avogadro}\mathrm{number}\left({\mathrm{N}}_{\mathrm{A}}\right)}$
• Therefore,
• $$\begin{gathered} \mathrm{n}=\frac{{10}^{22}}{6.022\times {10}^{23}} \\ =1.66\times {10}^{-2}\mathrm{moles} \end{gathered}$$

Answer: The number of moles of stars present in the visible universe is $1.66\times {10}^{-2}\mathrm{moles}$