5.Calculate the entropy changes for the following processes:(a)Melting of one mole of tin at its melting point, 213 ᵒC; ΔHfus = 7.029 kJ/mol(b)Evaporation of one mole of liquid carbon dioxide at its boiling point, 216.6 K. ΔHvap = 15.326 kJ/mol

a) ΔS = 14.46 J/k

b) ΔS = 70.76 J/k

Explanation:

The general formula to calculate the entropy change accompanied with a process is:

ΔS = ΔQ/T

where,

ΔS = entropy change for the process

ΔQ = Heat Transfer during the process

T = Absolute Temperature during the process

a)

In this case the heat transfer will be given as:

ΔQ = (ΔHfus)(N)

where,

ΔHfus = Molar Heat of Fusion of Tin = 7.029 KJ/mol

N = No. of moles of tin = 1 mol

Therefore,

ΔQ = (7.029 KJ/mol)(1 mol)

ΔQ = 7.029 KJ = 7029 J

and the absolute temperature is:

T = 213°C +273 = 486 k

using these values in the entropy formula, we get:

ΔS = 7029 J/486 k

ΔS = 14.46 J/k

b)

In this case the heat transfer will be given as:

ΔQ = (ΔHvap)(N)

where,

ΔHvap = Molar Heat of Vaporization of Carbon Dioxide = 15.326 KJ/mol

N = No. of moles of Carbon Dioxide = 1 mol

Therefore,

ΔQ = (15.326 KJ/mol)(1 mol)

ΔQ = 15.326 KJ = 15326 J

and the absolute temperature is:

T = 216.6 k

using these values in the entropy formula, we get:

ΔS = 15326 J/216.6 k

ΔS = 70.76 J/k

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles