A scientist wants to make a solution of tribasic sodium phosphate, \rm Na_3PO_4, for a laboratory experiment. How many grams of \rm Na_3PO_4 will be needed to produce 575 mL of a solution that has a concentration of \rm Na^+ ions of 1.00 \it M?

Answer 1

I really would like to know what \rm and
\it mean.

You want 1.0 M (I assume the \it is extraneous) Na^+ which means you want 1/3 molar Na3PO4.
M = moles/L. You know M and L, solve for moles.
Then moles = grams/molar mass. Solve for grams.
Check my thinking.

Answer 2

It means she was too lazy to do her homework or proofread what she is copying from her homework's website.