Answer:
The answer to your question is: the third option is correct.
Explanation:
"Alkenes" ________.
are reasonably soluble in water This option is incorrect, alkenes are insoluble in water.
are relatively polar compounds This option is wrong, alkenes are not polar molecules.
have lower boiling points than alcohols of similar molecular weight This option is true, alkenes have a lower boiling point than alcohols.
both have lower boiling points than alcohols of similar molecular weight and are relatively polar compounds. This option is incorrect because is combining true with false facts.
Calcium is a really soft type of metal.
~Deceptiøn
Answer:
The correct option is;
D)
Explanation:
The given reaction is presented as follows;
NH₄Cl (s) → NH₃ (g) + HCl (g) ΔH° = 176 kJ/mol, ΔS° = 0.285 kJ/(mol·K)
We note that the Gibbs free energy, ΔG° is represented by the following equation;
ΔG° = ΔH° - T·ΔS°
Where:
T = Temperature (Kelvin)
The reaction will be spontaneous for exergonic reactions, ΔG° < 0 and it will not be spontaneous for endergonic reaction, ΔG° > 0
At room temperature, T = 25 + 273.15 = 298.15 K
Which gives;
ΔG° = 176 - 298.15 × 0.285 = 91.03 kJ/mol which is > 0 Not spontaneous reaction
At 800°C, we have;
T = 273.15 + 800°C + 1073.15 K
ΔG° = 176 - 1073.15 * 0.285 = -129.85 kJ/mol which is < 0 the reaction will be spontaneous
The correct option is therefore, that at room temperature, the reaction is not spontaneous. However, at high temperatures. like 800 °C, the free energy value turns negative and this reaction becomes spontaneous.
Its mass will stay the same