Advertisements
Advertisements
Questions
In the extraction of aluminium: Write the function and formula of cryolite in the extraction of aluminium.
In the extraction of aluminium Write the function and chemical formula of cryolite
Advertisements
Solution
Cryolite is added to the molten mixture of alumina to reduce the melting point. The formula of cryolite is Na3AlF6.
APPEARS IN
RELATED QUESTIONS
In the extraction of aluminium: Name the process of concentration of bauxite.
Define the Ore.
Why does a new aluminium vessel lose shine so soon after use?
Explain giving one example, how highly reactive metals (which are high up in the reactivity series) are extracted.
Define the terms gangue.
Name two metals which are always found in combined state.
Give the principles of electromagnetic separation.
State why aluminium is extracted from its oxide by electrolysis while copper, lead, iron by reducing agents and mercury and silver by thermal decomposition.
Give reasons, why aluminum is used in:
painting electric and telegraphic poles
An element has its electron configuration as 2,8,8,2. Now answer the following questions.
a) What is the atomic number of this element?
b) What is the group of this element?
c) To which period does this element belong?
State one observation for each of the following :
Copper sulphate solution is electrolysed using copper electrodes.
Name the ore of mercury. With the help of balanced chemical equations, explain the process of extraction of mercury from its ore.
X is an element in the form of a powder. X burns in oxygen and the product is soluble in water. The solution is tested with litmus. Write down only the word which will correctly complete each of the following sentences:
(a) If X is a metal, then the litmus will turn ______.
(b) If X is a non-metal, then the litmus will turn ______.
(c) If X is a reactive metal, then ______ will be evolved, when X reacts with dilute sulphuric acid.
(d) If X is a non -metal, it will form _ oxide, which will form ______ solution with water.
(e) If X is a non -metal, it will not conduct electricity unless it is carbon in the form of ______.
Observe the given figure of reactivity series of metals and answer the following questions:
Reactivity series of metals
- Name two metals which react with water.
- Name two moderately reactive metals.
- Name the most highly reactive metal and the most less reactive metal.
Write the name.
The molecular formula of main ore of aluminium –
Explain the concept of Roasting.
Explain the following reaction with the balanced equation.
Chlorine dissolved in water
Explain the following reaction with the balanced equation.
Dry aluminium hydroxide is ignited at 1000 °C
Read the following passage and answer the questions.
According to the reactivity series, zinc is more reactive than iron, iron is more reactive than silver. During study of this, a student dipped the iron nails in silver nitrate solution.
- What is reactivity series?
- What will happen when iron nails are dipped in silver nitrate solution?
- Which type of reaction happens when iron metal reacts with silver nitrate solution?
- What will happen if a zinc rod is used instead of iron nail?
Answer the questions on the following passage.
The minerals from which the metal can be separated economically are called ores. Ores contain many types of impurities such as soil, sand and rocky substances along with metal compounds. These impurities are called gangue.
Metals can be extracted from their ores by means of various methods of separation. The process of extraction of metal in a pure state from the ores is also a part of metallurgy.
Ores are taken out from the mines and the gangue is usually separated from the ore at the site itself by various methods. Then the ores are carried out to the place where metals are produced. Here metals are extracted in pure form. Then metals are further purified by different methods of purification. This entire process is called metallurgy. Most metals being reactive do not occur in nature in the free state but are found in combined state as their salts such as oxides, carbonates, sulphides, and nitrates. however, the most unreactive metals that are not affected by air, water and other natural factors like silver, gold, platinum, generally occur in a free state. The compounds of metals that occur in nature along with the impurities are called minerals.
- What are ores?
- Which processes are involved in the branch of metallurgy? What is metallurgy?
- Which metals are found in a free state?
- In what forms are metals found in combined state?
- What is gangue?
