Question

How many joules of energy must be absorbed to convert into $L{i}^{+}$ all the atoms present in $1.00$ mg of gaseous $Li$? (IE)${}_1$ of $Li$ is 520.3 kJ mol${}^{-1}$?

• A. $74.3$
• B. $64.3$
• C. $80$
• D. None of these

Answer 1

Answer: (A)

$74.3$

$1.00$ mg of gaseous Li $=1\times {10}^{-3}g=\frac{1\times {10}^{-3}}{7}gmolLi$

1 mol of Li is converted by 520.3 kJ.

$\therefore \frac{1\times {10}^{-3}}{7}$ mol is converted to Li${}^{+}$ $=\frac{520\times 1\times {10}^{-3}}{7}kJ$

$=0.0743kJ=74.3joule$.