Answer : q = 6020 J, w = -6020 J, Δe = 0
Solution : Given,
Molar heat of fusion of ice = 6020 J/mole
Number of moles = 1 mole
Pressure = 1 atm
Molar heat of fusion : It is defined as the amount of energy required to melt 1 mole of a substance at its melting point. There is no temperature change.
The relation between heat and molar heat of fusion is,
(in terms of mass)
or,
(in terms of moles)
Now we have to calculate the value of q.

When temperature is constant then the system behaves isothermally and Δe is a temperature dependent variable.
So, the value of 
Now we have to calculate the value of w.
Formula used : 
where, q is heat required, w is work done and
is internal energy.
Now put all the given values in above formula, we get

w = -6020 J
Therefore, q = 6020 J, w = -6020 J, Δe = 0
Answer:
145 hours
Explanation:
Since one hour of riding a bicycle takes up 505 kcal of energy. It is also stated that one gram of body fat is equal to 7.70 kcal. Also, it is given that 1 pound of body fat is equal to 454 g.
Hence;
1 Ib= 454 g
21 Ib= 21 × 454/1 = 9534 g
But
1g of body fat = 7.70kcal
9534 g of body fat = 9534 × 7.70 kcal/1 = 73411.8 kcal
If 505 kcal is lost in 1 hour
73411.8 kcal is lost in 73411.8 kcal × 1hour/505k cal = 145 hours
It is a physical change because it only changed states
I would say that the answer has to be C
Since there is no change in mols on both sides of the equation the mass is constant