the normal freezing point of the element mercury, Hg(l), is a -38.9°C and its molar enthalpy of fusion, ΔHfusion=2.29 KJ/mol. What is the entropy change (J/K) of the system when 50 g of Hg(l) freezes at the normal freezing point. Hg= 200.59 g/mol
To calculate the entropy change (ΔS) of the system when 50 g of Hg(l) freezes at its normal freezing point, we need to use the equation:
ΔS = ΔHfusion / T
where ΔHfusion is the molar enthalpy of fusion and T is the temperature in Kelvin.
First, let's calculate the number of moles of Hg(l) in 50 g:
Number of moles = Mass / Molar mass
Number of moles = 50 g / 200.59 g/mol
Next, let's convert the normal freezing point temperature from Celsius to Kelvin:
T = -38.9 °C + 273.15
Now we can substitute these values into the equation for entropy change:
ΔS = (2.29 kJ/mol) / T
Make sure to convert kJ to J by multiplying by 1000:
ΔS = (2.29 kJ/mol) * (1000 J/1 kJ) / T
Finally, substitute the value of T into the equation and solve for ΔS:
ΔS = (2.29 kJ/mol) * (1000 J/1 kJ) / (T in Kelvin)
Calculate the value of ΔS using the given values, and the resulting ΔS will be in J/K.