Respuesta :

2.5 % w/v ( that means we have 2.5 grams of solute in 100 mL solution )

1.00 mL = 1000 mL therefore:

2.5 g ------------- 100 mL
?? --------------- 1000 mL

1000 x 2.5 / 100 => 25.0 g of NaCl