Yea same I tried so hard I think you need to get a expert or look this up on a website or something
Answer:
1200 J/K
Explanation:
The formula for the entropy associated with a reversible phase change is

1. Calculate q
For a reversible phase change like melting,

2. Calculate ΔS

Answer:
c) (12×0.9889) + (13×0.01108)
Explanation:
Given data:
Percentage of C-12 = 98.89%
Percentage of C-13 = 1.108%
Atomic mass = ?
Solution:
98.89/100 = 0.9889
1.108/ 100 = 0.01108
Atomic mass = (12×0.9889) + (13×0.01108)
Atomic mass = (11.8668 + 0.144034)
Atomic mass = 12.01084