Which of the following condition favours the reduction of a metal oxide to metal?

Q. Choose the incorrect combination.

\begin{matrix} Δ H & Δ S & Temperature & Spontaneity I. & \oplus v e & ⊖ v e & Any temperature & Non-spontaneous II. & ⊖ v e & ⊖ v e & Low temperature & Non-spontaneous III. & \oplus v e & \oplus v e & Low temperature & Spontaneous IV. & ⊖ v e & \oplus v e & Any temperature & Spontaneous \end{matrix}

Q. Choose the incorrect combination

\begin{matrix} Δ H & Δ S & Temperature & Spontanity I. & \oplus v e & ⊖ v e & Any temperature & Non-spontaneous II. & ⊖ v e & ⊖ v e & Low temperature & Non-spontaneous III. & \oplus v e & \oplus v e & Low temperature & Spontaneous IV. & ⊖ v e & \oplus v e & Any temperature & Spontaneous \end{matrix}

Q. Assertion :At low temperature,

Δ H

is the dominant factor for spontaneity of a reaction. Reason: The opposing factor

T Δ S

remains very small, at low temperature.

Q. Assertion :A process for which,

Δ S_{s y s t .} > 0

as well as

Δ H > 0

, passes from non-spontaneous to spontaneous state as temperature is increased Reason: At higher temperature,

T Δ S

exceeds

Δ H

Q. This section contains 1 Matrix Match type question, which has 2 Columns (Column I and Column II). Column I has four entries (A), (B), (C) and (D), Column II has four entries (P), (Q), (R) and (S). Match the entries in Column I with the entries in Column II. Each entry in Column I may match with one or more entries in Column II.

इस खण्ड में 1 मैट्रिक्स मिलान प्रकार का प्रश्न है, जिसमें 2 कॉलम (कॉलम I तथा कॉलम II) हैं। कॉलम I में चार प्रविष्टियाँ (A), (B), (C) तथा (D) हैं, कॉलम II में चार प्रविष्टियाँ (P), (Q), (R) तथा (S) हैं। कॉलम I में दी गयी प्रविष्टियों का मिलान कॉलम II में दी गयी प्रविष्टियों के साथ कीजिए। कॉलम I में दी गयी प्रत्येक प्रविष्टि का मिलान कॉलम II में दी गयी एक या अधिक प्रविष्टियों के साथ हो सकता है।

Match the Columns and choose the appropriate answer

कॉलमों का मिलान करें और सही उत्तर चुनें

Match the correct sign of ΔH and ΔS respectively in Column-I with the nature of process in Column-II.

कॉलम-I में दिये गये क्रमशः ΔH तथा ΔS के सही चिन्ह को कॉलम-II में दिये गये प्रक्रम की प्रकृति के साथ सुमेलित कीजिए।

	Column-I (Sign of ΔH and ΔS respectively) कॉलम-I (क्रमशः ΔH तथा ΔS के चिन्ह)		Column-II (Nature of process) कॉलम-II (प्रक्रम की प्रकृति)
(A)	–ve and +ve –ve तथा +ve	(P)	Non-spontaneous at all temperature सभी ताप पर अ-स्वतः
(B)	+ve and –ve +ve तथा –ve	(Q)	Spontaneous at all temperature सभी ताप पर स्वतः
(C)	–ve and –ve –ve तथा –ve	(R)	Spontaneous at high temperature उच्च ताप पर स्वतः
(D)	+ve and +ve +ve तथा +ve	(S)	Spontaneous at low temperature निम्न ताप पर स्वतः

Which of the following condition favours the reduction of a metal oxide to metal?

The correct option is C ΔH=−ve,TΔS=+ve at any temperatureAs ΔG=ΔH−TΔS So for the reduction of a metal oxide, ΔG value must be negative, and this can only be achieved among all given possibilities of ΔH and TΔS values, when the ΔH=−ve and TΔS=+ve at any temperature.