Question

The total number of electrons present in $5.6\text{L}$ of methane gas at STP is:

• A. $9.64\times {10}^{23}$
• B. $6.023\times {10}^{23}$
• C. $15.06\times {10}^{23}$
• D. $24.03\times {10}^{23}$

Answer 1

The correct option is C $15.06\times {10}^{23}$

$5.6\text{L}$ of methane gas at STP means $\frac{5.6\text{L}}{22.4\text{L}}=0.25$ mol of $C{H}_4$
1 mol of $C{H}_4$ contains 10 mol of electrons
$0.25\text{mol of}C{H}_4=10\times 0.25\text{mol of}{e}^{-}=2.5\text{mol of}{e}^{-}$
$1\text{mol}{e}^{-}=6.023\times {10}^{23}$ electrons
$2.5\text{mol}{e}^{-}=2.5\times 6.023\times {10}^{23}$ electrons
$=15.06\times {10}^{23}$ electrons.