Description : `DeltaG^(@) vsT` plot in the Ellingham diagram slopes down for the reaction.
Last Answer : `DeltaG^(@) vsT` plot in the Ellingham diagram slopes down for the reaction. A. `Mg+(1)/(2)O_(2)toMgO` B. ` ... (2)toCO` D. `CO+(1)/(2)O_(2)toCO_(2)`
Description : In which of the following reactions,standard reaction entropy change`(DeltaS^(@))`is positive and standard Gibb,s energy change`(DeltaG^(@))`decreases
Last Answer : In which of the following reactions,standard reaction entropy change`(DeltaS^(@))`is positive and standard Gibb,s ... (2)O_(2)(g)rarr CO_(2)(g)`
Description : According to Ellingham diagram the oxidation reaction of carbon and carbon monoxide may be used to reduce which one of the following oxides at the low
Last Answer : According to Ellingham diagram the oxidation reaction of carbon and carbon monoxide may be used to reduce which one of ... B. `Cu_(2)O` C. MgO D. ZnO
Description : Ellingham Diagram is useful
Last Answer : Ellingham Diagram is useful A. To know thetempreature where phase transformation ocuurs B. To know the ... of metal oxide D. All of the above
Description : Some statement about Ellingham diagram (a) Increase in the slope of the line on +ve side indicates the phase ransformation (b) Metal oxide decomposes
Last Answer : Some statement about Ellingham diagram (a) Increase in the slope of the line on +ve side indicates the phase ... C. Only b and c D. a,b and c
Description : Consider the following reactions at `1000^(@)C`. (A) `Zn_((s))+1/2 O_(2(g)) rarr ZnO_((s)), DeltaG^(@)=-360` kJ/mol (B) `C_("(gra)")+1/2 O_(2(g)) rarr
Last Answer : Consider the following reactions at `1000^(@)C`. (A) `Zn_((s))+1/2 O_(2(g)) rarr ZnO_((s)), DeltaG^( ... a) and (b) are true D. both (a) and (b) false
Description : In which of the following reactions, standard reaction entropy change (S°) is positive and standard Gibb's energy change (G°) decreases sharply with increasing temperature? (1) 2 2 1 1 1 C graphite O (g) CO (g) 2 2 2 (2) 2 1 C ... CO(g) O (g) CO (g) 2 (4) 2 1 Mg(s) O (g) MgO(s) 2
Last Answer : C graphite O (g) CO(g)
Description : Assertion :- Catalyst change Gibbs free energy of system. Reason :- Catalyst changes preexponential factor of a chemical reaction.
Last Answer : Assertion :- Catalyst change Gibbs free energy of system. Reason :- Catalyst changes preexponential factor ... . If both Assertion & Reason are false.
Description : Gibbs free energy per mole for a pure substance is equal to the (A) Latent heat of vaporisation (B) Chemical potential (C) Molal boiling point (D) Heat capacity
Last Answer : (B) Chemical potential
Description : Assertion (A): There is no reaction known for which `DeltaG` is positive, yet it is spontaneous. Reason (R ) : For photochemical reaction, `DeltaG` is
Last Answer : Assertion (A): There is no reaction known for which `DeltaG` is positive, yet it is spontaneous. ... False. D. If both Assertion & Reason are false.
Description : Assertion : Reduction of ZnO with carbon is done at `1100^(@)C`. Reason : At this temperature, `DeltaG^(@)` is negative and the process is spontaneous
Last Answer : Assertion : Reduction of ZnO with carbon is done at `1100^(@)C`. Reason : At this temperature, ... ^(@)` is negative and the process is spontaneous.
Description : (A): At 1200K iron can be reduce cuprous oxide (R )L: At 1200K, `Fe+Cu_(2)O to FeO+2Cu` `DeltaG=-300kj//"mole"`
Last Answer : (A): At 1200K iron can be reduce cuprous oxide (R )L: At 1200K, `Fe+Cu_(2)O to FeO+2Cu` ` ... incorrect D. If (A) is incorrect but (R ) is correct
Description : (A) The reduction reaction, `Cr_(2)O_(3)+2Al to Al_(2)O_(3)+2Cr, DeltaG^(0)=-421KJ` is not possible at room temperature (R ) Certain amount of activat
Last Answer : (A) The reduction reaction, `Cr_(2)O_(3)+2Al to Al_(2)O_(3)+2Cr, DeltaG^(0)=-421KJ` is not ... incorrect D. If (A) is incorrect but (R ) is correct
Description : Correct statements from the graph I) Above 1073 K,`DeltaG^(0)` for the formation of `F_(2)O_(3)` is less negative than `DeltaG^(0)` for the formation
Last Answer : Correct statements from the graph I) Above 1073 K,`DeltaG^(0)` for the formation of `F_(2)O_(3)` is less ... I B. I,II only C. I,II,III only D. All
Description : For the formation of metal oxide, `deltaG^(@)` __________ with increase in temperature.
Last Answer : For the formation of metal oxide, `deltaG^(@)` __________ with increase in temperature. A. Only I B. I,II only C. I,II,III only D. All
Description : Consider the following reaction at `1000^(@)C` `(A) Zn_((s))+(1)/(2)O_(2(s))+ZnO_(s),DeltaG^(0)=-360kJ"mole"^(-1)` (B) `(B) Cn_((s))+(1)/(2)O_(2(g))to
Last Answer : Consider the following reaction at `1000^(@)C` `(A) Zn_((s))+(1)/(2)O_(2(s))+ZnO_(s),DeltaG^ ... 1 and 2 are true D. Both statement 1 and 2 are false
Description : For which one of the following reaction, the graph of `DeltaG` against T is almost horizontal to temperature axis
Last Answer : For which one of the following reaction, the graph of `DeltaG` against T is almost horizontal to temperature axis A. ... ((s))+O_(2(g)) to 2MgO(g)`
Description : Pick out the wrong statement. (A) In a multistep reaction, the slowest step is the rate determining step (B) In general, the rate of a reaction becomes triple for every 10°C rise in temperature (C ... energy (D) Molecularity of a reaction cannot be zero but the order of a reaction can be zero
Last Answer : (B) In general, the rate of a reaction becomes triple for every 10°C rise in temperature
Description : Minimum gibbs free energy is NOT attained by a semipermeable membrane. True or false?
Last Answer : Can someone please help me with this question
Description : The Gibbs free energy change of a reaction at `27^(@)C` is -26 Kcal. and its entropy change is -60 Cals/K. `Delta H` for the reaction is :-
Last Answer : The Gibbs free energy change of a reaction at `27^(@)C` is -26 Kcal. and its entropy change is -60 Cals/K. ... Cals. C. 34 K. Cals. D. `-24` K. Cals.
Description : In what way will the gibbs free energy always be negative?
Last Answer : What is the answer ?
Description : How does the Gibbs free energy predict spontaneity?
Last Answer : If G is negative, then the answer is spontaneous
Description : If a reaction has an enthalpy of -54.32 kJ/mol and an entropy of -354.2 J/(K*mol), what is the Gibbs free Energy at 54.3(degrees c)?
Last Answer : DeltaG = DeltaH - TDeltaS dG = -54.32 kJ/mol - (54'32+273)K(-354.2J/molK) NB Thevtemperature is quoted in Kelvin(K) and the Entropy must be converted to kJ by dividing by '1000'/ Hence dG = ... 115.94 kJ/mol dG = (+)61.61 kJ/mol Since dG is positive, the reaction is NOT thermodynamically feasible.
Description : Boiling of liquid is accompanied with increase in the (A) Vapor pressure (B) Specific Gibbs free energy (C) Specific entropy (D) All (A), (B) and (C)
Last Answer : (A) Vapor pressure
Description : (∂H/∂T)P is the mathematical expression for (A) CV (B) Entropy change (C) Gibbs free energy (D) None of these
Last Answer : (D) None of these
Description : Specific/molar Gibbs free energy for a pure substance does not change during (A) Sublimation (B) Vaporisation (C) Melting (D) Either (A), (B) or (C)
Last Answer : (D) Either (A), (B) or (C)
Description : The change in Gibbs free energy for vaporisation of a pure substance is (A) Positive (B) Negative (C) Zero (D) May be positive or negative
Last Answer : (C) Zero
Description : Gibbs free energy of a pure fluid approaches __________ as the pressure tends to zero at constant temperature. (A) Infinity (B) Minus infinity (C) Zero (D) None of these
Last Answer : (B) Minus infinity
Description : Gibbs free energy at constant pressure and temperature under equilibrium conditions is (A) ∞ (B) 0 (C) Maximum (D) Minimum
Last Answer : (D) Minimum
Description : If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as (A) Solubility increases as temperature ... (D) Solubility increases or decreases with temperature depending on the Gibbs free energy change of solution
Last Answer : (B) Solubility increases as temperature decreases
Description : In any spontaneous process, the __________ free energy decreases. (A) Helmholtz (B) Gibbs (C) Both ‘a’ & ‘b’ (D) Neither 'a' nor 'b'
Last Answer : (C) Both ‘a’ & ‘b’
Description : Specific __________ does not change during phase change at constant temperature and pressure. (A) Entropy (B) Gibbs energy (C) Internal energy (D) Enthalpy
Last Answer : (B) Gibbs energy
Description : Specific __________ does not change during a phase change (e.g. sublimation, melting, vaporisation etc.). (A) Entropy (B) Internal energy (C) Enthalpy (D) Gibbs free energy
Last Answer : (D) Gibbs free energy
Description : Gibbs free energy of mixing at constant pressure and temperature is always (A) 0 (B) ∞ (C) + ve (D) - ve
Last Answer : (D) - ve
Description : The standard Gibbs free energy change of a reaction depends on the equilibrium (A) Pressure (B) Temperature (C) Composition (D) All (A), (B) and (C)
Last Answer : (B) Temperature
Description : The molar excess Gibbs free energy, gE, for a binary liquid mixture at T and P is given by, (gE/RT) = A . x1. x2, where A is a constant. The corresponding equation for ln y1, where y1is the activity co-efficient of component 1, is (A) A . x22 (B) Ax1 (C) Ax2 (D) Ax12
Last Answer : (A) A . x22
Description : The change in __________ is equal to the reversible work for compression in steady state flow process under isothermal condition. (A) Internal energy (B) Enthalpy (C) Gibbs free energy (D) Helmholtz free energy
Last Answer : (C) Gibbs free energy
Description : Gibbs free energy (G) is represented by, G = H - TS, whereas Helmholtz free energy, (A) is given by, A = E - TS. Which of the following is the Gibbs Helmholtz equation? (A) [∂(G/T)/∂T] = - (H/T2) (B) [∂(A/T)/∂T]V = - E/T2 (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B)
Description : _________ does not change during phase transformation processes like sublimation, melting & vaporisation. (A) Entropy (B) Gibbs free energy (C) Internal energy (D) All (A), (B) & (C)
Last Answer : (B) Gibbs free energy
Description : Write A Short Note On Gibbs Free Energy And Derive The Equation For The Same.?
Last Answer : This thermodynamic quantity states that the decrease in value during a process is equal to the useful work done by the system. It is denoted by G and the mathematical equation is: G = H - TS Where ... of the system Thus the above equation becomes: ΔG = ΔH - TΔS is known as Gibbs-Helmoholtz equation.
Description : _________ is a thermodynamic potential that measures the “useful” or process-initiating work obtainable from an isothermal, isobaric thermodynamic system. a. Du-Pont Potential b. Gibbs free energy c. Rabz-Eccles Energy d. Claussius Energy
Last Answer : Gibbs free energy
Description : The temperature at which the magnetic property of iron disappears (i.e., it becomes non-magnetic) and its electrical conductivity & specific heat also changes, is called the 'Curie point', which is __________ °C. (A) 768 (B) 908 (C) 1400 (D) 1539
Last Answer : Option A
Description : If the rate of a chemical reaction becomes slower at a given temperature, then the (A) Initial concentration of the reactants remains constant (B) Free energy of activation is lower (C) Entropy changes (D) Free energy of activation is higher
Last Answer : (D) Free energy of activation is higher
Description : The minimum energy required to allow a chemical reaction to proceed is termed as the 'threshold energy '. Chemical reactions with low activation energy are: (A) Always irreversible (B) Insensitive to temperature changes (C) Mostly irreversible (D) Highly temperature sensitive
Last Answer : (B) Insensitive to temperature changes
Description : Immediate allergy reaction (type I allergic reaction) is: a) An allergic or immune response that begins within a period lasting from a few minutes to about an hour after exposure to an ... cause tissue damage e) It occurs during blood transfusion reactions and in hemolytic disease of the newborn.
Last Answer : Ans: A
Description : How dehydration helps in the preservation of food? (a) Growth of micro-organism is checked (b) Nutrients are concentrated (c) Surface of food stuffs becomes hard (d) Chemical reactions stop in the absence of water
Last Answer : Ans:(a)
Description : A(5,0) and B(0,8) are two vertices of triangle OAB. a). What is the equation of the bisector of angle OAB. b). If E is the point of intersection of this bisector and the line through A and B,find the coordinates of E. Hence show that OA:OB = AE:EB -Maths 9th
Last Answer : NEED ANSWER
Last Answer : This answer was deleted by our moderators...
Description : If circles are drawn taking two sides of a triangle as diameter, prove that the point of intersection of these circles lie on the third side. -Maths 9th
Last Answer : Solution :- Given: Two circles are drawn on sides AB and AC of a △ABC as diameters. The circles intersects at D. To prove: D lies on BC Construction: Join A and D Proof: ∠ADB = 90° (Angle in the semi-circle ... + 90° => ∠ADB + ∠ADC = 180° => BDC is a straight line. Hence, D lies On third side BC.
Description : If two equal chords bisect each other, then the point of intersection of the chords coincides with their centre. [True `//` False]
Last Answer : If two equal chords bisect each other, then the point of intersection of the chords coincides with their centre. [True `//` False]