The density of a 0.438 M solution of potassium chromate (K2CrO4) at 298 K is 1.063 g>mL. Calculate the vapor pressure of water above the solution. The vapor pressure of pure water at this temperature is 0.0313 atm. (Assume complete dissociation of the solute.)

Video transcript

Hi everyone today, we have a question telling us that an injectable sodium chloride solution, 0.154 Mueller sodium chloride has a density of 0.9981 g per milliliter at 40.0 degrees Celsius. And our question is, what is the vapor pressure of the solution? Pure water has a vapor pressure of 0.07 - eight atmosphere at this temperature. So we will first find out the mole fraction of water. Using the solution polarity and density, We have 0. Mueller sodium chloride Equals 0.154 marbles of sodium chloride. In one L Solution. There will be twice the solid particles than the molds of sodium chloride because sodium chloride will dissociate into sodium and whoring the solute particles equals two times 0.154 moles, Which equals 0.308 moles. The mass of our solution equals one leader, Times one mil liter, divided by 10 to the negative. 3rd leader, times zero point 9981 g Over one mil liter. And our leaders here are canceling out and our male leaders are canceling out, Leaving us with g. And that equals 998.1 g. Our mass of sodium chloride Equals 0.154 moles of sodium chloride times .44g over one mole. And our moles are canceling out here giving us nine zero g sodium chloride. Our massive water equals nine 198.1 g -9.00 g Equals 989 0.1 g. Our moles of water Equals .1g of water times one mole Over the molar mass of water, which is 18.02 g. And our grams are canceling out here, Leaving us with 54 . moles. So our ex water equals 54 .89 moles, divided by 54. moles plus zero point 308 moles Equals 0.9944. Our pressure of our solution Equals 0.994. four times 0. to eight atmospheres Equals 0. Atmospheres. And that is our final answer. Thank you for watching. Bye.