Answer:
-4741 °C
Something is strange, because this is a weird number.
Explanation:
ΔT = Kf . m. i
That's the colligative property of freezing point depression.
Kf = Cyroscopic constant
m = molality (moles of solute in 1kg of solvent)
i = Van't Hoff factor (numbers of ions dissolved)
We assume 100% dissociation:
CaCl₂ → Ca²⁺ + 2Cl⁻ i = 3
ΔT = Freezing point of pure solvent - Freezing point of solution
Let's determine molality
Solute = CaCl₂
Moles of solute = 23.5 g . 1 mol/ 110.98 g = 0.212 moles
We determine the mass of solvent by density. Density's data is in g/L. We need to convert the volume from mL to L
250 mL . 1L / 1000 mL = 0.250 L
0.997 g/L = mass of water / volume of water → 0.997 g/L . volume of water = mass of water
0.997 g/L . 0.250L = 0.249 g
Now, we convert the mass of water from g to kg
0.249 g . 1 kg / 1000 g = 2.49×10⁻⁴ kg
Molality = mol/kg → 0.212 mol / 2.49×10⁻⁴ kg = 850.5 m
We replace data:
0°C - Freezing point of solution = 1.858 °C . kg /mol . 850.5 mol/kg . 3
Freezing point of solution = -4741 °C
Answer:
C) P3– > Cl– > K+ > Ca2+
Explanation:
Ionic radius can be defined as the distance between the nucleus and the electron in the outermost shell of atom in its ionic state. When an atom looses an electrons(Cation) its ionic radius decreases, whereas when an atom gains an electron(anion), its ionic radius increases.
Among the given ions the ionic radius of
all distances are in picometer.
clearly,
option C is correct that is
C) P3– > Cl– > K+ > Ca2+
