Answer:
NaI > Na2SO4 > Co Br3
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.
Answer:
8kJ/mol
Explanation:
since the forward reaction is -8kJ/mol, the backward reaction has the same enthalphy but reversed
Answer is: <span>unbalanced electronegativity of the hydrogens and oxygens as they share electrons.
Oxygen has greater electronegativity than hydrogen, because of that oxygen is partially negative and hydrogen is partially positive.
</span>Electronegativity<span> is a </span>chemical property<span> that describes the tendency of an </span>atom<span> to attract a shared pair of </span>electrons<span> towards itself.</span>
The k is the proportionality constant of the reaction. Graphically, this is the slope of the graph. Since the graph is linear, then there is only 1 value of k. To calculate this, choose two random points in the line. Suppose we use (0.15,10) and (0.30,20), calculate for the slope.
Slope = k = (10 - 20)/(0.15 - 0.30) = 66.67 mL CO₂/g CaCO₃
Answer:
The answer to your question is: m = 37.88 g
Explanation:
Data
Copper Water
mass ? 95.7 g
Cp 0.092 cal/g°C 1 cal/g°C
T1 65.4°C 22.7°C
T2 24.2°C 24.2°C
Formula
Q copper = Q water
Q = mCp(T2 - T1)
- m(0.092)(24.2 - 65.4) = 95.7(1)(24.2 - 22.7)
m = 95.7(1)(24.2 - 22.7) /- (0.92)(24.2 - 65.4)
m = 143.55 / 3.79
m = 37.88 g
