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प्रश्न
Explain the following reaction with the balanced equation.
Dry aluminium hydroxide is ignited at 1000 °C
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उत्तर
When dry aluminium hydroxide is calcined by at 1000 °C, pure aluminium oxide, called alumina is obtained.
\[\ce{\underset{\text{Aluminium hydroxide}}{2Al(OH)_{3(s)}} ->[heat][1000 °C] \underset{\text{Aluminium oxide}}{Al2O_{3(s)}} + \underset{\text{Water vapour}}{3H2O_{(g)}}}\]
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संबंधित प्रश्न
Fill in the following blank with suitable word:
Bronze is an alloy of copper and .........
How is manganese extracted from manganese dioxide, MnO2? Explain with the help of an equation.
How is zinc extracted from its carbonate or (calamine)? Explain with equations.
The major ore of aluminium is known as:
(a) cinnabar
(b) calamine
(c) bauxite
(d) pyrolusite
Which of the following pair of metals exists in their native state in nature?
(a) Ag and Hg
(b) Ag and Zn
(c) Au and Hg
(d) Au and Ag
In an electrolytic tank, aluminium metal is being extracted by the electrolysis of molten aluminium oxide using carbon electrodes. It is observed that one of the carbon electrodes is gradually burnt away and has to be replaced.
(a) Which carbon electrode (cathode or anode) is burnt away?
(b) Why is this carbon electrode burnt away?
Which metal can be extracted from the following ore?
bauxite
Define the following term.
Gangue
Answer the following questions based on the extraction of aluminium from alumina by Hall - Heroult’s Process :
Name the electrode, from which aluminium collected.
Name a non- metal that has a metallic luster and sublimes on heating.
Calcium, copper, lead, aluminium, zinc, chromium, magnesium, iron.
Choose the major metals from the list given above to make the following alloys:
(a) Stainless steel
(b) brass
Carbon cannot reduce the oxides of sodium, magnesium, and aluminum to their respective metals. Why? Where are these metals placed in the reactivity series? How are these metals obtained from their ores? Take an example to explain the process of extraction along with chemical equations.
How is the method of extraction of metals high up in the reactivity series different from that for metals in the middle? Why can the same process not be applied for them? Name the process used for the extraction of these metals.
Write the name.
Metals which are amphoteric in nature.
Gold and silver are active metals.
Complete flow chart given below.
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.
Two ores A and B were taken. On heating ore A gives CO2 whereas, ore B gives SO2. What steps will you take to convert them into metals?
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.
