ExamGOAL
Books
PreviousNext
13
MCQ (Single Correct Answer)

For the reduction of FeO at the temperature corresponding to point D , which of the following statements is correct?

A
$\Delta G$ value for the overall reduction reaction with carbon monoxide is zero.
B
$\Delta G$ value for the overall reduction reaction with a mixture of 1 mol carbon and 1 mol oxygen is positive.
C
$\Delta G$ value for the overall reduction reaction with a mixture of 2 mol carbon and 1 mol oxygen will be positive.
D
$\Delta G$ value for the overall reduction reaction with carbon monoxide is negative.
14
MCQ (Multiple Correct Answer)

At the temperature corresponding to which of the points in Fig. FeO will be reduced to Fe by coupling the reaction $2 \mathrm{FeO} \longrightarrow \mathrm{WFe}+\mathrm{O}_2$ with all of the following reactions?

$$\text { 1. } \mathrm{C}+\mathrm{O} \longrightarrow \mathrm{CO}_2$$

$$\begin{aligned} & \text { 2. } 2 \mathrm{C}+\mathrm{O}_2 \longrightarrow 2 \mathrm{CO} \\ & \text { 3. } 2 \mathrm{CO}+\mathrm{O}_2 \longrightarrow 2 \mathrm{CO}_2 \end{aligned}$$

A
Point $A$
B
Point $B$
C
Point $D$
D
Point $E$
15
MCQ (Multiple Correct Answer)

Which of the following options are correct?

A
Cast iron is obtained by remelting pig iron with scrap iron and coke using hot air blast.
B
In extraction of silver, silver is extracted as cationic complex.
C
Nickel is purified by zone refining.
D
Zr and Ti are purified by van Arkel method.
16
MCQ (Multiple Correct Answer)

In the extraction of aluminium by Hall-Heroult process, purified $\mathrm{Al}_2 \mathrm{O}_3$ is mixed with $\mathrm{CaF}_2$ to

A
lower the melting point of $\mathrm{Al}_2 \mathrm{O}_3$
B
increase the conductivity of molten mixture.
C
reduce $\mathrm{Al}^{3+}$ into $\mathrm{Al}(\mathrm{s})$
D
acts as catalyst
17
MCQ (Multiple Correct Answer)

Which of the following statements is correct about the role of substances added in the froth floatation process?

A
Collectors enhance the non-wettability of the mineral particles.
B
Collectors enhance the wettability of gangue particles.
C
By using depressants in the process two sulphide ores can be separated.
D
Froth stabilisers decrease wettability of gangue.
PreviousNext