Explanation:
solar and energy i had to answer this one before
The answer would be: C. 160.3 J/mol*K
To solve this question, you need to know the equation for Gibbs free energy formula. Entropy is expressed as delta S. The temperature would be expressed as T. Don't forget that temperature use Kelvin as unit, not Celsius
The formula would be:
G= H- T*S
130.5 kJ/mol= 178.3kJ/mol - (25+273.15K)*S
(298.15K)*S=178.3kJ/mol - 130.5 kJ/mol
S= (47.8kJ/mol)/ 298.15K=
S= 0.1603 kJ/mol*K= 160.3 J/mol*K ------> 1kJ= 1000J
all of the above.
The properties of water are:
1) polar molecules
2) regulates temperature
3) universal solvent
4) high surface tension
5) can exist in all three stages of matter
Answer:
136.5°C
Explanation:
Given data
- Boiling point of X: 134.5°C
- Molal boiling point elevation constant (Kb): 1.36·°C·kg.mol⁻¹
We can calculate the elevation in the boiling point (ΔT) using the following expression.
ΔT = Kb × m
where,
m is the molality
The molar mass of urea is 60.06 g/mol. The moles of urea corresponding to 76 g is:
76 g × (1 mol/60.06g) = 1.3 mol
The mass of the solvent (X) is 850 g = 0.850 kg.
The molality is:
m = 1.3 mol / 0.850 kg = 1.5 mol/kg
Then,
ΔT = Kb × m
ΔT = 1.36·°C·kg.mol⁻¹ × 1.5 mol/kg
ΔT = 2.0 °C
The boiling point of the solution is
134.5°C + 2.0°C = 136.5°C
