Answer:
The solution's boiling point is 100,2°C and its molality is 0,13 m
Explanation:
This is the colligative propertie about elevation of boiling point
ΔT = Kb . m . i where
ΔT is the difference between T° at boiling point of the solution - T° at boiling point of the solvent pure
Kb means ebulloscopic constant (0,52 °C.kg/m .- a known value for water)
m means molality (moles of solute in 1kg of solvent)
i means theVan 't Hoff factor ( degree of dissociation for a compound)
IT HAS NO UNITS
NiI2 ---> Ni2+ + 2I- (we have 1 Ni2+ and 2 I-), the i for this, is 3
The 11,11 g of the salt are in 272,2g of water but I need to know how many mass of the salt is in 1000 g of water (1000 g is 1 kg) so the rule of three is:
272,2g ____ 11,11g
1000g _____ (1000 g . 11,11g) / 272,2g = 40,81g
As the molar mas of NiI2 is 312.5 g/mol, the moles of salt are, mass/molar mass, 40,81g /312.5 g/mol = 0,130 moles
T° of b p sl - 100°C = 0,52 °C.kg/m . 0,130 m/kg . 3
T° of boiling point solution = (0,52 °C.kg/m . 0,130 m/kg . 3) + 100°C
T° of boiling point solution = 100,2°C
