One mole of NaCl weighs 58.44 grams
Therefore 1L of one mole of NaCl contains 58.44 grams
1L of 0.2m NaCl contains 58.44x0.2 = 11.69grams
300mL of 0.2m NaCl contains 11.69x0.3 = 3.51 grams
An mL is also equivalent to cm³, signifying that 140 mL is equivalent to 140 cm³. The mass of ethanol is calculated by multiplying the density by the volume.
mass = (140 cm³)(0.789 g/cm³)
mass = 110.46 g
Then, calculate the number of moles of ethanol by dividing the mass by the molar mass of ethanol equal to 46.07 g/mol.
number of moles = (110.46 g/ 46.07 g/mol) = 2.4 mol
Then, multiply the number of moles by the Avogadro's number.
2.4 mol (6.022 x 10²³)
<em> number of molecules = 1.445 x 10²⁴</em>
The gas has already created enough pressure to become a gas, which is the most expandable it could turn in to. Thats what i think, hope it helps.