What is the mass ratio of ethylene glycol ( C _ 2 H _ 6 O _ 2 ,...

The molality of aqueous ethylene glycol solution = 0.25 m

Mass of ethylene glycol required for 1000 g water = $\dfrac{62}{4} = 15 . 5gm$

Mass of solution = 1015.5 gm

Mass of ethylene glycol in 500 gm solution $= \dfrac{15 . 5 \times 500}{1015 . 5} = 7 . 63gm$

Assuming density of solution as 1 gm/mL.

Mass of ethylene glycol in 250 mL $= \dfrac{7 . 63}{2} = 3 . 815gm$

Mass ratio of ethylene glycol for making 500 gm of 0.25 m solution and 250 mL of 0.25 m solution = $2: 1$

So, the correct option is C