Answer:
The correct answer is B. It is spontaneous only at low temperatures.
Explanation:
In thermodynamics, the Gibbs free energy is a thermodynamic potential that can be used to calculate the maximum of reversible work that may be performed by a thermodynamic system at a constant temperature and pressure.
The spontaneity of a reaction is given by the equation:
ΔG = ΔH - TΔS
where:
ΔH: enthalpy variation
T: absolute temperature
ΔS: entropy variation
As the reaction is exothermic, ΔH<0
As the reaction order increases (the reagents are solid and gas and their product is solid), ΔS<0
Therefore, the reaction will be spontaneous when ΔG is negative.
ΔG = ΔH - TΔS
That is, the entropy term must be smaller than the enthalpy term.
Hence, the reaction will be spontaneous only at low temperatures.
Answer:
The following reaction will occur at cathode:

Explanation:
The two half reaction during electrolysis of aqueous nickel sulfate will be
a) anode reaction :
Water will undergo oxidation and will evolve oxygen gas at anode as shown in the given reaction:

b) Cathode reaction: The reduction of Nickel ion will occur by gain of two electrons as shown in the given equation:

Thus the overall reaction will be:

A or D I think but go with A it makes more since
Answer:
Actual yield = 86.5g
Explanation:
Percent yield = 82.38%
Theoretical yield = 105g
Actual yield = x
Equation of reaction,
CaCO₃ + HCl → CaCl₂ + CO₂ + H₂O
Percentage yield = (actual yield / theoretical yield) * 100
82.38% = actual yield / theoretical yield
82.38 / 100 = x / 105
Cross multiply and make x the subject of formula
X = (105 * 82.38) / 100
X = 86.499g
X = 86.5g
Actual yield of CaCl₂ is 86.5g