meaning that NaI has the highest freezing point, and Co Br3 has the lowest freezing point.
Explanation:
The freezing point depression is a colligative property.
That means that it depends on the number of solute particles dissolved.
The formula to calculate the freezing point depression of a solution of a non volatile solute is:
ΔTf = i * Kf * m
Where kf is a constant, m is the molality and i is the van't Hoff factor.
Molality, which is number of moles per kg of solvent, counts for the number of moles dissolved and the van't Hoff factor multipllies according for molecules that dissociate.
The higher the number of molecules that dissociate, the higher the van't Hoff, the greater the freezing point depression and the lower the freezing point.
As the question states that you assume equal concentrations (molality) and complete dissociation you just must find the number of ions generated by each solute, in this way:
NH4 I → NH4(+) + I(-) => 2 ions
Co Br3 → Co(+) + 3 Br(-) => 4 ions
Na2SO4 → 2Na(+) + SO4(2-) => 3 ions.
So, Co Br3 is the solute that generate more particles and that solution will exhibit the lowest freezing point among the options given, Na2SO4 is next and the NaI is the third. Ordering the freezing point from higher to lower the rank is NaI > Na2SO4 > CoBr3, which is the answer given.
Sodium hypochlorite chemical name would be NaOCl. Then, the molecular weight should be:23 + 16 + 35.5 = <span>74.5 g/mole
Molarity unit is mole of molecule divided by 1000ml of solvent, in this case water. Then for 32.4g of molecule with 499ml solvent it would be: 32.4g / (74.5g/mole) / (1000ml/499ml)= 0.87 m</span>
The atomic radius (r) of an atom can be defined as one half the distance (d) between two nucli in a diatomic molecule. Atomic radii have been measured for elements. The units for atomic radii are picometers, equal to 10−12 meters.
Polyester is a condensation polymer of dicarboxylic acid and diol.
Example : Polethylene terphthalate is polymer of ethylene glycol and tere phthallic acid.
When a strong acid like HCl or a strong base like NaOH comes in contact with polyester (like spilled on slacks) it causes hydrolysis of polyester and it get converted back to dicarboxylic and diol(the monomers).
the general reaction will be
RCOOR' ---> RCOOH + R'OH
Thus slacks will get teared.