Answer:
A reaction is non-spontaneous at any temperature when the Gibbs free energy > 0.
Explanation:
There is a state function, that determines if a reaction is sponaneous or non spontaneous:
ΔG = Gibbs free energy
A reaction is non spontaneous when it does require energy to produce that reaction. It will be spontaneous, when the reaction does not require energy to be occured.
The formula is: ΔG = ΔH - T.ΔS
ΔH → Enthalpy → Energy gained or realeased as heat.
ΔH < 0 → <em>Exothermic reaction. Spontaneity is favored
</em>
T → Temperature
ΔS → Entropy → Degree of disorder of a system.
When the system has a considered disorder ΔS > 0, disorder increases.
When the system is more ordered, ΔS < 0, disorder decreases.
The reaction will be non spontaneous if, the enthalpy is positive (endothermic reaction) and the ΔS < 0 (disorder decreases). It will not occur if we do not give energy.
ΔG < 0 → Spontaneous reaction
ΔG > 0 → Non spontaneous reaction
ΔG = 0 → System in equilibrium
Answer:
2.1 x 10⁻².
Explanation:
- Generally, the equilibrium constant (Keq) is the product of the concentration of the reaction products divided by the product of the concentration of the reaction reactants, each term is raised to a power equal to its coefficient in the balanced chemical reaction.
- For the given reaction: 2HF → H₂ + F₂,
Keq = [H₂][F₂] / [HF]²,
Keq = [H₂][F₂] / [HF]² = [8.4 x 10⁻³][8.4 x 10⁻³] / [5.82 x 10⁻²]² = 2.1 x 10⁻².
Acetic anhydride is the only monocarboxylic acid anhydride which is an acylating agent capable of modifying reactions. The dichloromethane is the reaction solvent.
The acetic anhydride should be added slowly through a separatory funnel to other reactants so as to avoid a runaway reaction, also known as thermal runaway. By doing this the reaction mixture boils as gently as possible while stirring. This phenomenon occurs in situations where an increase in temperature changes the conditions in a way that leads to destructive result brought about by a further increase in temperature.
Answer: С
. The temperature increases by about 12°C and then decreases by about 12°C.
Explanation:
Temperatures around the world have been on the rise since the Industrial revolution as humans clog the planet with Carbon Dioxide and other pollutants. This had led to a rise in temperatures that has seen ice levels fall and sea levels rise around the world.
Temperature fluctuations on the other hand are not a new thing. Studies show that in Antarctica temperatures from about 440,000 years ago to about 340,000 years ago increased by 12°C and then decreased by about 12°C.
