Ellingham Diagram

Q. The point of intersection and sudden increase in the slope, in the diagram given below respectively, indicates:

1. $\Delta G=0$ and melting or boiling point of the metal oxide.

2. $\Delta G<0$ and decomposition of the metal oxide.

3. $\Delta G=0$ and reduction of the metal oxide.

4. $\Delta G>0$ and decomposition of the metal oxide.

Q. The rate constants for decomposition of acetaldehyde have been measured over the temperature range $700-1000K$. The data has been analysed by plotting In k vs $\frac{{10}^3}{T}$ graph. The
value of activation energy for the reaction is
$kJmo{l}^{-1}$ (Nearest integer)
$\text{(Given: R = 8.31}J{K}^{-1}mo{l}^{-1})$

Q.

Which metal has the highest thermal expansion?

Q.

Out of C and$C{O}_1$ which is a better reducing agent at 673 K?

Q. For spontaneous polymerization, which of the following is (are) correct?

1. $\Delta G$ is negative
2. $\Delta H$ is negative
3. $\Delta s$ is positive
4. $\Delta s$ is negative

Q. Consider the following reaction at ${1000}^{\circ }\text{C}$,
$i.Zn\left(s\right)+\frac{1}{2}{O}_2\left(g\right)\to ZnO\left(s\right);\Delta G=-360\text{KJ/mol}$
$ii.C\left(s\right)+\frac{1}{2}{O}_2\left(g\right)\to CO\left(s\right);\Delta G=-460\text{KJ/mol}$
Then choose the correct statement from the following

1. Zinc can be oxidized by $CO$
2. $ZnO$ can be reduced by $C$
3. $ZnO$ can be reduced by $CO$
4. None of the above

Q. Given below are two statements .

Statement I : The choice of reducing agents for metals extraction can be made by using Ellingham diagram , a plot of $\Delta G^o$ vs temperature.

Statement II : The value of $\Delta S$ increases from left to right in Ellingham diagram .

In the light of the above statements , choose the most appropriate answer from the options given below :

Q. Match the extraction process listed in column I with metals listed in column II.

Column I	Column II
A. Self reduction	P. Lead
B. Carbon reduction	Q. Silver
C. Complex formation and displacement by metal	R. Copper
D. Electrolytic reduction	S. Sodium

1. $A\to P,R;B\to P;C\to Q;D\to S$
2. $A\to P;B\to P,R;C\to Q;D\to S$
3. $A\to Q;B\to S,R;C\to Q;D\to P$
4. $A\to R,S;B\to P;C\to Q;D\to R$

Q.

The carbon – based reduction method is not used for the extraction of

1. tin from $Sn{O}_2$

2. iron from $F{e}_2{O}_3$

3. aluminium from $A{l}_2{O}_3$

4. magnesium from $MgC{O}_3,CaC{O}_3$

Q. You are given the following reduction reactions and $E^{\circ }$ values:
$F{e}^{3+}\left(aq\right)+e^{-}\to F{e}^{2+}\left(aq\right)E^{\circ }=+0.771\text{V}$
$F{e}^{2+}\left(aq\right)+2e^{-}\to Fe\left(s\right)E^{\circ }=-0.447\text{V}$
Calculate $E^{\circ }$ for the half-cell reaction $F{e}^{3+}\left(aq\right)+3e^{-}\to Fe\left(s\right)$.

1. $+0.32\text{V}$
2. $+1.22\text{V}$
3. $-0.04\text{V}$
4. $+0.04\text{V}$

Q. With respect to an ore, Ellingham diagram helps to predict the feasibility of its:

1. Electrolysis
2. Thermal reduction
3. Vapour phase refining
4. Zone refining

Q. Which of the following statements is/are correct regarding the following diagram of reduction of haematite?

1. Below 1073 K, $C$ is a better reducing agent.
2. Below 1073 K, $CO$ is a better reducing agent.
3. Above 1073 K, $C$ is a better reducing agent.
4. Haematite can’t be reduced by $C$ or $CO$.

Q.

Give an example of a chemical reaction in which a tremendous amount of heat is released.

Q. How many of the following metals is extracted by self reduction process?
$Pb,Au,Mg,Sn,Fe,Al,Ag,Hg,Na,Zn,Cu,Ca$

Q.

The point of intersection and sudden increase in the slope, in the diagram given below respectively, indicates:

1. ΔG = 0 and melting or boiling point of the metal oxide.

2. ΔG < 0 and decomposition of the metal oxide.

3. ΔG = 0 and reduction of the metal oxide.

4. ΔG > 0 and decomposition of the metal oxide.

Q. The extraction of metals from oxide ores involve(s):

1. Reduction with carbon
2. Reduction with aluminium
3. Electrolytic reduction
4. Reduction with CO

Q. How many of the following metals is extracted by self reduction process?
$Pb,Au,Mg,Sn,Fe,Al,Ag,Hg,Na,Zn,Cu,Ca$

Q. Ellingham diagram is a graphical representation of:

1. $\Delta G$ vs $T$
2. $(\Delta G-T\Delta S)$ vs $T$
3. $\Delta H$ vs $T$
4. $\Delta G$ vs $P$

Q. Boron can be obtained by various methods but not by ;

1. pyrolysis of $B{l}_3$ (Van Arkel).
2. reducing $BC{l}_3$ with $H_2$.
3. electrolysis of fused $BC{l}_3$.
4. thermal decomposition of $B_2{H}_6$.

Q.
Which of the following is incorrect on the basis of the above Ellingham diagram for carbon?

1. Up to ${710}^{\circ }C$, the reaction of formation of $C{O}_2$ is energetically more favorable, but above ${710}^{\circ }C$, the formation of $CO$ is preferred.
2. In principle, carbon can be used to reduce any metal oxide at a sufficiently high temperature.
3. $\Delta S(C_{\left(s\right)}+\frac{1}{2}{O}_{2\left(g\right)}\to C{O}_{\left(g\right)})<\Delta S(C_{\left(S\right)}+O_{2\left(g\right)}\to C{O}_{2\left(g\right)})$
4. Carbon reduces many oxides at elevated temperature because $\Delta G^{\circ }$ vs temperature line has a negative slope.

Q. Which of the following statements is/are correct regarding the following diagram of reduction of haematite?

1. Below 1073 K, $C$ is a better reducing agent.
2. Below 1073 K, $CO$ is a better reducing agent.
3. Above 1073 K, $C$ is a better reducing agent.
4. Haematite can’t be reduced by $C$ or $CO$.

Q. Match items of Column I with the items of Column II and assign the correct code:

1. a - (iv), b - (ii), c - (iii), d - (i)
2. a - (ii), b - (iii), c - (i), d - (v)
3. a - (i), b - (ii), c - (iii), d - (iv)
4. a - (iii), b - (iv), c - (v), d - (i)

Q. Select the incorrect option for the Ellingham diagram ($\Delta G^{\circ }$ versus T).

1. Positive value of ${\Delta }_f{G}^{\circ }for{M}_{x}O$ indicates, $M_{x}O$ decompose on its own
2. Metal with most -ve value of $\Delta G^{\circ }$ for formation of oxide can act as a better reducing agent
3. $\Delta G^{\circ }$ is plotted for the oxidation of metal with 1 mole of $O_2$
4. $\Delta G^{\circ }$ is plotted for reduction of 1 mole of metal oxide

Q. 10. In the metallurgy of iron the reducing agent will be coke or CO. When coke is burned then CO is produced that this CO doea the reduction so what will be considered here

Q. A metal forms two oxides. The higher oxide contains 80% metal.0.72 g of the lower oxide gave 0.8g of the higher oxide when oxidize then the ratio of weight of oxygen that combines with fixed weight of metal in the two oxides will be (a) 2:3 (b)1:2 (c)4:5 (d)3:2

Q. Considering Ellingham diagram, which of the following metals can be used to reduced alumina?

1. $Mg$
2. $Fe$
3. $Cu$
4. $Zn$

Q. What are ellingham diagrams ? Write any two features of it.

Q. Is it true that under certain conditions $Mg$ can reduce $A{l}_2{O}_3$ and $Al$ can reduce $MgO$ ? What are those conditions?

Q. According to Ellingham diagram, the oxidation reaction of carbon to carbon monoxide may be used to reduce which one of the following oxides at the lowest temperature?

1. $A{l}_2{O}_3$
2. $C{u}_{2}O$
3. $MgO$
4. $ZnO$

Q. In a first order reaction graph between t half and concentration