Answer
Please see the work below.
Work Step by Step
We have the required balanced chemical equation as
$3H_3PO_3+2HNO_3\rightarrow 3H_3PO_4+2NO+H_2O$
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.