Explanation:
Relation between entropy change and specific heat is as follows.

The given data is as follows.
mass = 500 g,
= 24.4 J/mol K
= 500 K,
= 250 K
Mass number of copper = 63.54 g /mol
Number of moles = 
= 
= 7.86 moles
Now, equating the entropy change for both the substances as follows.
= ![7.86 \times 24.4 \times [500 -T_{f}]](https://tex.z-dn.net/?f=7.86%20%5Ctimes%2024.4%20%5Ctimes%20%5B500%20-T_%7Bf%7D%5D)

= 750
So,
= 
- For the metal block A, change in entropy is as follows.

= ![24.4 log [\frac{375}{500}]](https://tex.z-dn.net/?f=24.4%20log%20%5B%5Cfrac%7B375%7D%7B500%7D%5D)
= -3.04 J/ K mol
- For the block B, change in entropy is as follows.

= ![24.4 log [\frac{375}{250}]](https://tex.z-dn.net/?f=24.4%20log%20%5B%5Cfrac%7B375%7D%7B250%7D%5D)
= 4.296 J/Kmol
And, total entropy change will be as follows.
= 4.296 + (-3.04)
= 1.256 J/Kmol
Thus, we can conclude that change in entropy of block A is -3.04 J/ K mol and change in entropy of block B is 4.296 J/Kmol.
To calculate<span> the average </span>atomic mass<span>, multiply the fraction by the </span>mass<span> number for each isotope, then add them together.</span>
Answer:
∆H is negative
∆S is negative
Explanation:
The condensation of CS2 implies a phase change from gaseous state to liquid state. The energy of the gaseous particles is greater than that of the liquid particles hence energy is given out when a substance changes from gaseous state to liquid state hence the process is exothermic and ∆H is negative.
Changing from gaseous state to liquid states leads to a decrease in entropy hence ∆S is negative. Liquid particles are more orderly than particles of a gas.
Non-renewable resources, such as coal, produce harmful gasses, such as carbon monoxide, polluting the air and decreasing air quality.