Question

Calculate the number of moles of electrons present in 18.2 g of electrons:

• A. $3.32\times {10}^8$ mol
• B. $1.12\times {10}^8$ mol
• C. $3.32\times {10}^4$ mol
• D. $1.12\times {10}^4$ mol

Answer 1

The correct option is C $3.32\times {10}^4$ mol

We know,
Mass of one electron = $9.1\times {10}^{-31}kg$
So mass of one mole of electron = $9.1\times {10}^{-31}\times 6.022\times {10}^{23}kg$

So number of moles in $18.2\times {10}^{-3}kg$ electron
$=\frac{18.2\times {10}^{-3}}{9.1\times {10}^{-31}\times 6.022\times {10}^{23}}mol$
$=3.32\times {10}^{4}mol$