Smelting

Q.

Write the reaction when zinc carbonate is heated.

Q.

When hydrogen peroxide is added to acidified potassium dichromate, the blue colour produced is due to the formation of

1. ${\mathrm{Cr}}_2{\mathrm{O}}_3$

2. ${\mathrm{CrO}}_5$

3. ${\mathrm{CrO}}_3$

4. ${\mathrm{Cr}}_2{{\mathrm{O}}_7}^{2-}$

Q.

Write chemical reactions taking place in the extraction of zinc from zinc blende.

Q. What is carbide?

Q.

Why do metal ion having higher reduction potential reduces first??

Q.

What are the impurities present in bauxite?

Q. Which of the following is strongest reducing agent and why. Zn, . H2, Cr, Fe,

Q.

Which compound is used in making LED?

Q. The metal which is found in nature are called and metal which can be extracted conveniently, economically in large quantities are called

1. matrix
2. ores
3. minerals
4. nuggets

Q.

Heating an aqueous solution of aluminium chloride to dryness will give

1. 

2. 

3. 

4. 

Q.

State the reactions that take place at the cathode and anode during the process of electrolytic reduction of Alumina (Al₂O₃).

Q.

name the gases liberated at anode and cathode respectively when an aqueous solution of Nacl is electrolysed

Q. what is doping? explain its types.

Q.

Give reason for the following observation

Aluminum can only be extracted by electrolytic reduction of its oxide not by carbon reduction

Q.

Why the reduction process is always involved in the extraction of metals?

Q.

Coke and Flux are used in smelting. Why?

Q. hybridization of carbon in urea

Q. Name the method used for refining of copper metal.

Q.

The chemical formula of Chile salt petre is:

1. NaNO₃

2. Na₂SO₄

3. NaNO₂

4. Na(NO₃₎₂

Q.

What is red mud and is it removed ?

Q.

Name of metal, M which is extracted based on the following equation,

$4\mathrm{M}+8{\mathrm{CN}}^{-}+2{\mathrm{H}}_2\mathrm{O}+{\mathrm{O}}_2\to 4[\mathrm{M}{\left(\mathrm{CN}\right)}_2{]}^{-}+4{\mathrm{OH}}^{-}$

$2[\mathrm{M}{\left(\mathrm{CN}\right)}_2{]}^{-}+\mathrm{Zn}\to {\left[\mathrm{Zn}\right({\mathrm{CN}}_4\left)\right]}^{2-}+2\mathrm{M}$

1. (a) Cu

2. (b) Au

3. (c) Hg

4. (d) Ni

Q.

Which metal can be extracted by smelting?

1. $\mathrm{Pb}$

2. $\mathrm{Fe}$

3. $\mathrm{Zn}$

4. $\mathrm{Al}$

Q.

Assertion – The non-fusible impurities present in iron ore are removed by $CaC{O}_3$ .

Reason: $CaC{O}_3$ which decomposes into $CaO$ and $C{O}_2$. The $CaO$ formed reacts with $Si{O}_2$ to remove silica

1. Both assertion and reason are correct and the reason is the correct explanation for the assertion.

2. Both assertion and reason are correct but reason is not the correct explanation for the assertion.

3. Assertion is correct but reason is wrong

4. Assertion is incorrect but reason is correct

5. Both assertion and reason are wrong.

Q. Which of the following sulphides when heated strongly in air gives the corresponding metal without undergoing separate reduction of oxide?

1. $C{u}_{2}S$
2. $FeS$
3. $HgS$
4. $ZnS$

Q. DO KINETIC ENERGY OF PHOTOELECTRON DEPEND ON SURFACE AREA OF METAL?

Q.

Name a chemical used for dissolving aluminum oxide. In which state of subdivision is the chemical used?

Q.

Assertion – The non-fusible impurities present in iron ore are removed by $CaC{O}_3$ .

Reason: $CaC{O}_3$ which decomposes into $CaO$ and $C{O}_2$. The $CaO$ formed reacts with $Si{O}_2$ to remove silica

1. Both assertion and reason are correct and the reason is the correct explanation for the assertion.

2. Both assertion and reason are correct but reason is not the correct explanation for the assertion.

3. Assertion is correct but reason is wrong

4. Assertion is incorrect but reason is correct

5. Both assertion and reason are wrong.

Q.

1. True
2. False

Q.

Aluminium metal is frequently used as a reducing agent for the extraction of metals such as chromium and manganese from their respective oxides, why?

Q. Which of the following process is for purification of metals?

1. Froath floatation
2. Leaching
3. Liquation
4. Poling