Advertisements
Advertisements
Question
Explain the following reaction with the balanced equation.
Dry aluminium hydroxide is ignited at 1000 °C
Advertisements
Solution
When dry aluminium hydroxide is calcined by at 1000 °C, pure aluminium oxide, called alumina is obtained.
\[\ce{\underset{\text{Aluminium hydroxide}}{2Al(OH)_{3(s)}} ->[heat][1000 °C] \underset{\text{Aluminium oxide}}{Al2O_{3(s)}} + \underset{\text{Water vapour}}{3H2O_{(g)}}}\]
APPEARS IN
RELATED QUESTIONS
Metallic oxides of zinc, magnesium and copper were heated with the following metals.
| Metal | Zinc | Magnesium | Copper |
| Zinc oxide | – | – | – |
| Magnesium oxide | – | – | – |
| Copper oxide | – | – | – |
In which cases will you find displacement reactions taking place?
Define the term gangue.
Explain giving equation, what happens when:
A mixture of Cu2O and Cu2S is heated.
Name one ore of aluminium. Name the aluminium compound present in this ore and write its chemical formula.
Which gas is produced during the extraction of aluminium? At which electrode is this gas produced?
A black metal oxide XO2 is used as a catalyst in the preparation of oxygen gas from potassium chlorate. The oxide XO2 is also used in ordinary dry cells. The metal oxide XO2 cannot be reduced satisfactorily with carbon to form metal X.
- Name the metal X.
- Name the metal oxide XO2.
- Which reducing agent can be used to reduce XO2 to obtain metal X?
- Name another metal which can also be extracted by the reduction of its oxide with the above reducing agent.
Aluminum is used in thermite welding:
what is ignition mixture?
Aluminum is used in thermite welding:
write reaction for process?
Name the following:
The process in which an ore is heated in air so that oxygen gets added to it to form the oxides.
Name:
The allotrope of the non-metal carbon which conducts electricity.
Name the following:
A steel grey coloured solid non-metal.
Zinc blende is converted to oxide by ______ process.
Atomic number of aluminium is _______ and its electronic configuration is _______.
Extraction of moderately reactive elements is done by _______ and _______ method.
In Electrolytic reduction of alumina, Anode : _______ : : Cathode : Graphite lining
Explain the following reaction with the balanced equation.
Zinc carbonate is heated strongly in limited supply of air
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.
On the basis of reactivity metals are grouped into three categories:
- Metals of low reactivity
- Metals of medium reactivity
- Metals of high reactivity
Therefore metals are extracted in pure form from their ores on the basis of their chemical properties.
Metals of high reactivity are extracted from their ores by electrolysis of the molten ore.
Metals of low reactivity are extracted from their sulphide ores, which are converted into their oxides. The oxides of these metals are reduced to metals by simple heating.
(a) Name the process of reduction used for a metal that gives vigorous reaction with air and water both.
(b) Carbon cannot be used as a reducing agent to obtain aluminium from its oxide? Why?
(c) Describe briefly the method to obtain mercury from cinnabar. Write the chemical equation for the reactions involved in the process.
OR
(c) Differentiate between roasting and calcination giving chemical equation for each.
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 the reason why the above reaction is known as a thermite reaction.
