Advertisements
Advertisements
प्रश्न
Observe the figure and answer the following.
- Write the name of the method.
- What is used as anode and cathode in this method?
- Write the molecular formula and use of cryolite.
- Write anode reaction.
- Write cathode reaction.
Advertisements
उत्तर
- The method shown is an electrolytic reduction of alumina.
- A set of graphite rods dipped in the molten electrolyte acts as the anode. and the graphite lining acts as a cathode.
- Molecular formula of cryolite: Na3AlF6
Use of cryolite: Addition of cryolite reduces the melting point of alumina to about 1000 °C. - Anode reaction: \[\ce{2O^2+ -> O2 + 4e^-}\]
- Cathode reaction: \[\ce{Al^3+ + 3e^- -> Al_{(l)}}\]
APPEARS IN
संबंधित प्रश्न
Write the steps involved in the extraction of pure metals in the middle of the activity series from their carbonate ores.
Name the gas in air which tarnishes silver articles slowly.
Why do gold ornaments look new even after several years of use?
Fill in the following blank with suitable word:
Bronze is an alloy of copper and .........
Give the name and chemical formula of one ore of copper.
Name three other metals which are extracted in a manner similar to sodium.
How is copper extracted from its sulphide ore (copper glance), Cu2S? Explain with equations of the reactions involved.
Calamine ore can be used to extract one of the following metals. This metal is:
(a) copper
(b) mercury
(c) aluminium
(d) zinc
Which of the following reactants are used to carry out the thermite reaction required for welding the broken railway tracks?
(a) Al2O3 + Fe
(b) MnO2 + Al
(c) Fe2O3 + Al
(d) Cu2O + Fe
The metal which can be extracted simply by heating the cinnabar ore in air is:
(a) Zn
(b) Cu
(c) Al
(d) Hg
Give reasons, why aluminum is used in:
painting electric and telegraphic poles
Give reasons, why aluminum is used in:
In aluminiothermy
Name the following:
The mixture of materials fed into a furnace to extract a metal.
Compare the process of calcination and roasting.
Name the following:
The process of heating an ore to a high temperature in the presence of air.
Answer the following question :
What is the difference between calcination and roasting.
Atomic number of aluminium is _______ and its electronic configuration is _______.
Explain the following reaction with the balanced equation.
Dry aluminium hydroxide is ignited at 1000 °C
Oxides of moderately reactive metals like Zinc, Iron, Nickel, Tin, Copper, etc. are reduced by using:
The given reaction shows one of the processes to extract the metals like Iron and Manganese.
\[\ce{MnO2(s) + Al(s) -> Mn(l) + Al2O3(s) + Heat}\]
Give a reason why Aluminium is preferably used in thermite reactions.
