Correct Answer: C) ?S< 0 and ?H > 0

Explanation

This Chemistry question is asking about the spontaneity of a reaction at different temperatures. Spontaneity refers to whether or not a reaction can occur on its own without any external force or intervention.

The question provides four options to choose from. Option A states that the reaction is spontaneous if the change in Gibbs free energy, ?G, is equal to zero. Option B states that the reaction is spontaneous if ?G is greater than zero. Option C, which is the correct answer, states that the reaction is spontaneous if the change in entropy, ?S, is less than zero and the change in enthalpy, ?H, is greater than zero. Option D states that the reaction is spontaneous if ?S is greater than zero and ?H is less than zero.

It is important to note that while ?G is a good indicator of spontaneity, it is not the only factor that determines whether or not a reaction will occur spontaneously. In fact, ?G takes into account both ?S and ?H, which are the factors mentioned in option C.

Entropy, ?S, refers to the degree of disorder or randomness in a system. A negative ?S means that the system becomes more ordered, while a positive ?S means that the system becomes more disordered. Enthalpy, ?H, refers to the heat energy released or absorbed during a reaction. A positive ?H means that the reaction absorbs heat energy, while a negative ?H means that the reaction releases heat energy.

In summary, a reaction is spontaneous at all temperatures if ?S is less than zero and ?H is greater than zero, which is option C. This means that the reaction will occur on its own without any external force or intervention. It is important to understand that while ?G is a good indicator of spontaneity, it is not the only factor to consider.

Explanation

(ii) At the anode Cu\(_{(s)}\) - 2e\(^-\) -> Cu\(^{2+}\)\(_{(ag)}\); At the cathode Cu\(^{2+}\) + 2e \(\to\) Cu\(_{(s)}\)

(iii) Daniell cell is an electrochemical cell because chemical energy (from the reaction between the electrodes and the solution) is converted into electrical energy.

(iv) The function of MnO\(_2\) in the Leclanche cell Pure copper plate is to serve as depolarizer that is preventing the impure copper (cathode) hydrogen gas from adhering to the anode.

(b)(i) In MnO\(^-_4\) - + 8H\(^+\) + xe\(^-\) \(\to\) Mn\(^{2+}\) + yH\(_2\)O ; x = 5, y = 4

(ii) The oxidation of Mn in MnO\(^-_4\) is +7.

(c)(i) - Position of the ions in the electro-chemical series

-Concentration of the ions in the electrolyte

-Nature of the electrode.

(ii) Faraday's second law oxosulphate of electrolysis states that when the same quantity of electricity is passed through different electrolytes the relative number of moles of the elements discharged are inversely proportional to the charge on the ions of each of the elements respectively.

(iii) AgNO\(_3\) and CuSO\(_4\) ; Ag\(^+\) + e\(^-\) -> Ag\(_{(s)}\) ; Cu\(^{2+}\) + 2e\(^-\) -> Cu\(_{(s)}\)

96500C will liberate 108; It liberated 0.780

It = \(\frac{0.780}{108}\) x 96500C = 696.9C

(d)(i) 2 x 96500 C will liberate 63.50 ; 696.9C will liberate

= \(\frac{696.9}{2 \times 96500}\) x 63.50 = 0.2293g.

(ii) The quantity of electricity = 696.2 C.

but Q = It ; 0.200 x t = 696.9

t = \(\frac{696.9}{0.200}\) = 3484.5s; = 58.075 mins.

Correct Answer: A. collisions are perfectly elastic

Correct Answer: C) H2SO4

Correct Answer: B. conservation of matter

Correct Answer: D. Nitrogen oxide

Correct Answer: D. vanadium(v)oxide

Explanation

During the Contact Process for manufacturing sulfuric acid, sulfur dioxide has to be converted into sulfur trioxide, which is done by passing sulfur dioxide and oxygen over a solid vanadium(V) oxide catalyst.

Correct Answer: A) volume

Correct Answer: C. More of X2 will react

Correct Answer: C. -848