A 0.250 g sample of the weak acid HA (molar mass = 150.0 g/mol) is dissolved in 50.0 g of water. The freezing point of the resulting solution is -0.071°C. Calculate the value of Ka for this acid. Assume molality equals molarity in this solution. (Kf for water is 1.86°C/m.)

hey there!

mass = 6.75 g

volume =   9 cm³

therefore:

d = mass / volume

d   = 6.75 / 9

d = 0.7 g/cm³

answer b

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.