Answer
Please see the work below.
Work Step by Step
We know that
$Q=mL_f$
This can be rearranged as:
$m=\frac{Q}{L_f}$
We plug in the known values to obtain:
$m=\frac{4.18\times 10^{15}}{33400}$
$m=1.3\times 10^{10}Kg$
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.