White phosphorus reacts with aqueous NaOH to form \(PH_3(g)\) and sodium hypophosphite. When 6.2g of white phosphorus reacted with 500 mL of xM NaOH solution, the concentration of sodium hypophosphite in the resultant solution was \(0.3 \text{ mol L}^{-1}\). What are x (in M) and weight (in g) of \(PH_3\) formed respectively? (\(P=31\) u; \(H=1\) u; \(O=16\) u)