Electrometallurgy

Q.

What is the chemical formula of Bauxite?

Q.

1 mol of iron( Fe) reacts completely with 0.65 mol of O₂ to give a mixture of only FeO and Fe₂O₃ . mole ratio of ferrous oxide to ferric oxide is

Give the solution using some short cut method

Q.

Difference between Hoopes and serpecks processes.

Q.

Name the anode used in Hall-Heroults process of electrolysis.

Q. In the following reaction: 3Fe + 4H2O----> Fe3O4 +4H2O, if the atomic weight of iron is 56, then its equivalent weight will be?

Q.

An ore of potassium is:

1. bauxite

2. dolomite

3. carnallite

4. cryolite

Q. In conc.$HN{O}_3$ aluminium becomes passive due to the formation of a layer of

1. 
2. 
3. 
4. 

Q. (a) Write the cell reaction and calculate the e.m.f of the following cell at 298 K :

Sn(s) $S{n}^{2+}$ (0.004 M) || $H^{+}$ (0.020 M) | $H_2\left(g\right)$ (1 bar) | Pt (s)

(Given : $E_{S{n}^{2+}/Sn}^{\circ }$ = -0.14 V)

(b) Give reasons :

(i) On the basis of $E^{\circ }$ values, $O_2$ gas should be liberated at anode but it is $C{l}_2$ gas which is liberated in the electrolysis of aqueous NaCl.

(ii) Conductivity of $C{H}_{3}COOH$ decreases on dilution.

Q.

Write the constituents of electrolyte for the extraction of aluminium.

Q.

Name one metal that forms an amalgam.

Q.

In the ore Bauxite $A{l}_2{O}_3.2H_{2}O$ there are two significant types – Red Bauxite and White Bauxite. Bayer’s process is applicable for __ Bauxite.

Q. Each of the three metals x, y and z were put in turn into aqueous solution of the other two. x + salt of y (or z) = y (or z) + salt of x. Which one of the following observation is incorrect? (1) y + salt of x = no action observed (2) y + salt of z = z + salt of y (3) z + salt of x = x + salt of z (4) z + salt of y = no action observed

Q.

When fused Lead bromide is electrolyzed we observe:

1. A silver-grey deposit at the anode and a reddish-brown deposit at the cathode

2. A silver-grey deposit at the cathode and a reddish-brown deposit at the anode

3. A silver-grey deposit at the cathode and reddish-brown fumes at the anode.

4. Silver grey fumes at the anode and reddish fumes at the cathode.

Q. 16. A+3B=P. Δ H=-2xkj/mole of A M=2Q+R. Δ H=x kj/mole of M. If these reactions are carried simultaneously in a reactor such that temperature is not changing. If rate of disappearance of B is Y/sec then rate of formation (in M/sec) of Q is

Q. 69. In the lower temperature range of blast furnace {Fe_2O_3 first reduced to { (1) Fe_3O_4{ (2) FeO (3) Fe (4) Mixture of Fe and Feo

Q.

Impure copper has to be purified using electrolysis. Which of the following is correct?

1. Impure rod should be connected to positive terminal of the battery

2. Impure rod should be made to react with I₂

3. A heater should be moved on impure rod

4. Impure rod should be connected to negative terminal of the battery

Q.

What is the role of graphite rod in the electrometallurgy of aluminimum ?

Q.

For the electrorefining of copper:

1. What is the cathode made up of ?
2. Write the reaction that takes place at the anode.

Q. Arrange the following metals in the order in which they displace each other from the solution of their salts.
$Al,Cu,Fe,Mg$ and $Zn$

Q. Which of the following metal is used for drying organic solvent?

1. Li
2. Na
3. K
4. Cs

Q.

What should be the considerations during the extraction of metals by electrochemical method?

Q. Metals extracted by electrolysis of their fused salts are :

1. highly electropositive
2. highly electronegative
3. Both A and B
4. None of the above

Q. Match the information given in the three columns of the following table. The only combination in which $C{O}_2$ is passed for neutralization is:

Column 1: Metal

Column 2: Ores

Column 3: Composition

$\begin{array}{cccccc}& \text{Column 1}& & \text{Column 2}& & \text{Column 3}\\ \left(I\right)& \text{Aluminium}& \left(i\right)& \text{Haematite}& \left(P\right)& CuFe{S}_2\\ \left(II\right)& \text{Iron}& \left(ii\right)& \text{Zinc blende}& \left(Q\right)& Al{O}_x(OH{)}_{3-2x}\\ \left(III\right)& \text{Copper}& \left(iii\right)& \text{Bauxite}& \left(R\right)& F{e}_2{O}_3\\ \left(IV\right)& \text{Zinc}& \left(iv\right)& \text{Copper pyrite}& \left(S\right)& ZnS\end{array}$

1. (II) (iv) (S)
2. (I) (iv) (P)
3. (I) (iii) (S)
4. (I) (iii) (Q)

Q.

Describe the role of Graphite in the extraction process of aluminium.

Q. What is blister copper?

Q.

How Do You Extract Highly Reactive Metals?

Q. 35 Carbon reduction process is not commercially applicable for which of the following set of oxides to extract the respective metal? ZnO, Fe2O3, Al2O3, SnO2, MgO A ZnO, Fe2O3, SnO2 B ZnO, SnO2, MgO C MgO, Al2O3 D. MgO, SnO2, Al2O3

Q.

When fused Lead bromide is electrolyzed we observe:

1. A silver-grey deposit at the anode and a reddish-brown deposit at the cathode

2. A silver-grey deposit at the cathode and a reddish-brown deposit at the anode

3. A silver-grey deposit at the cathode and reddish-brown fumes at the anode.

4. Silver grey fumes at the anode and reddish fumes at the cathode.

Q. 8. Electrolysis of X gives Y at anode. Vacuum distillation of Y gives h2o2. The number of peroxy bonds present in X and Y are

Q. The common impurity present in bauxite is:

1. $A{l}_2{O}_3.H_{2}O$
2. $MgC{l}_2.CaC{l}_2$
3. $AlC{l}_3.A{I}_2{O}_3$
4. $F{e}_2{O}_3$