Answer
$emf = 1.5~V$
Work Step by Step
We can find the $emf$:
$W = Q~(emf)$
$emf = \frac{W}{Q}$
$emf = \frac{2.4\times 10^{-19}~J}{1.6\times 10^{-19}~C}$
$emf = 1.5~V$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.