Predict how the entropy of the substance is affected in the following processes:
CH₄ (g, 125°C)   →   CH₄ (g, 200°C)

For the reaction

$NaCl\left(s\right)\stackrel{water}{\to }N{a}^{+}\left(aq\right)+C{l}^{\text{–}}\left(aq\right),\Delta H=\text{+1 kcal/mol (+4.184 kJ/mol)}$

b. Does entropy increase or decrease in this process?

For the reaction 2 Hg(l) + O₂(g) → 2 HgO(s), ∆H = –43 kcal/mol (–180 kJ/mol).

a. Does entropy increase or decrease in this process? Explain.

The following reaction is used in the industrial synthesis of polyvinyl chloride (PVC) polymer:

Cl₂(g) + H₂C=CH₂(g) → ClCH₂CH₂Cl(l) ∆H = –52 kcal/mol (–218 kJ/mol)

a. Is ∆S positive or negative for this process?

PRACTICE: Which reaction is most likely to have a positive ∆S of system?

a) SiO₂ (s) + 3 C (s) → SiC (s) + 2 CO (g)

b) 6 CO₂ (g) + 6 H₂O (g) → C₆H₁₂O₆ (s) + 6 O₂ (g)

c) CO (g) + Cl₂ (g) → COCl₂ (g)

d) 3 NO₂ (g) + H₂O (l) → 2 HNO₃ (l) + NO (g)

Which of the following processes shows a decrease in entropy of the system?

Does entropy increase or decrease in the following processes?

c. 2 SO₂(g) + O₂(g) → 2 SO₃(g)

Does entropy increase or decrease in the following processes?

a. Polymeric complex carbohydrates are metabolized by the body, converted into smaller simple sugars.

Which of the following processes results in an increase in entropy of the system?

a. A drop of ink spreading out when it is placed in water

b. Steam condensing into drops on windows

c. Constructing a building from loose bricks