Calculate the no. of moles of solute present in 1.25cm cune of 0.5m h3po4

Answer 1

You must mean 1.25 cm^3.
I have no idea what cune is.
You must mean 0.5 M and not 0.05 m. I will assume you meant 0.5 M.
mols H3PO4 = M x L = ?. That's 0.5 M x (1.25 cm^3/1000 cm^3) = ?

Answer 2

answer is 625 cm3