Ellingham Diagram

Q.

For the following question, the answer is an integer between 0 and 9 (both inclusive).

In the Ellingham diagram for oxides, there are x lines for the reaction(s) between C and O. What is x?

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Q.

In the Ellingham diagram for oxides, the general trend for the graphs for metal to metal oxide is

1. There is no common trend

2. They slope upwards

3. They are all parallel to the ∆Gº = 0 horizontal axis

4. They slope downwards like the 2C + O₂ ⟶ 2CO line

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.

You are given an Ellingham diagram (deliberately not shown). It is given that for almost all practically achievable temperatures, the $Fe\to F{e}_2{O}_3$ line lies above the $Al\to A{l}_2{O}_3$ line and ${\Delta }_f{G}^{\circ }$ for both $A{l}_2{O}_3$ and $F{e}_2{O}_3$ are negative. Which of the following statements is/are true?

1. Under the given conditions, neither metal can reduce the other oxide

2. Both b and c

3. Fe can reduce $A{l}_2{O}_3$ into Al

4. Al can reduce $F{e}_2{O}_3$ into Fe

Q. The carbon-based reduction method is NOT used for the extraction of
(IIT-JEE, 2013)

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.

The $\frac{{\Delta }_f{G}^{\circ }}{T}$ line for $C+O_2$ $\to$ $C{O}_2$ is nearly parallel to the ${\Delta }_f{G}^{\circ }$ = 0 – True or False?

1. True

2. False

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. $\Delta S(C_{\left(s\right)}+\frac{1}{2}{O}_{2\left(g\right)}\to C{O}_{\left(g\right)})<\Delta S(C_{\left(S\right)}+O_{2\left(g\right)}\to C{O}_{2\left(g\right)})$
3. In principle, carbon can be used to reduce any metal oxide at a sufficiently high temperature.
4. Carbon reduces many oxides at elevated temperature because $\Delta G^{\circ }$ vs temperature line has a negative slope.

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. Reaction(s) involved in thermite process can be

1. $3M{n}_3{O}_4+8Al\to 9Mn+4A{l}_2{O}_3$
2. $C{r}_2{O}_3+2Al\to A{l}_2{O}_3+2Cr$
3. $2Fe+A{l}_2{O}_3\to 2Al+F{e}_2{O}_3$
4. $3Ti{O}_2\left(s\right)$ $+4Al\left(s\right)$ $\to$ $2A{l}_2{O}_3$ $\left(s\right)$ $+3Ti\left(l\right)$

Q.

The metal that cannot be extracted by reduction of its oxide with Aluminium is:

1. Fe

2. Mn

3. Ba

4. Cr