Explain the following
i. Carbon reduction process is not applied for reducing aluminium oxide to aluminium.
ii. Aq Sodium chloride cannot be used for the isolation of sodium by electrolytic reduction method.
iii. Thermite process is quite useful for repairing the broken parts of machines.

Why is the reduction of a metal oxide easier if the metal formed is in liquid state at the temperature of reduction?

While washing a miner's overalls, a washer woman noticed that sand and similar dirt fell to the bottom of the wash tub. What was peculiar, the copper bearing compounds that had come to the clothes from the mines were caught in the soaplids and so they came to the top. One of her clients was a chemist, Mrs. Malik. The washer woman told her experience to Mrs. Malik. The latter thought that the idea could be used for separating copper compounds from rocky and earth materials on a large scale. After reading the above passage answer the following questions-
(i) Name the process of concentration of ore based on the observation of washer woman.
(ii) What type of ores are concentrated by this process?
(iii) What values are shown by washer woman and Mrs.Malik?

While washing a miner's overalls, a washerwoman noticed that sand and similar dirt fell to the bottom of the washtub. What was peculiar, the copper-bearing compounds that had come to the clothes from the mines were caught in the soaplids and so they came to the top. One of her clients was a chemist, Mrs. Malik. The washerwoman told her experience to Mrs. Malik. The latter thought that the idea could be used for separating copper compounds from rocky and earth materials on a large scale. After reading the above passage answer the following questions-
What type of ores are concentrated by this process?

While washing a miner's overalls, a washer woman noticed that sand and similar dirt fell to the bottom of the wash tub. What was peculiar, the copper bearing compounds that had come to the clothes from the mines were caught in the soaplids and so they came to the top. One of her clients was a chemist, Mrs. Malik. The washer woman told her experience to Mrs. Malik. The latter thought that the idea could be used for separating copper compounds from rocky and earth materials on a large scale. After reading the above passage answer the following questions-
What values are shown by washer woman and Mrs.Malik?

In roasting, the are is heated in a regular supply of air in furnace at a temperature below the melting point of the metal. Metal sulphide gets converted into metal oxide and sulphur dioxide gas is formed
which is air pollutant. It also leads to the formation of acid rain which is harmful for crops and buildings made from marble.
(i) Where should we have industries using roasting process in metallurgy? Give reason.
(ii) How can sulphuric acid help in national economy?

In roasting, the are is heated in a regular supply of air in furnace at a temperature below the melting point of the metal. Metal sulphide gets converted into metal oxide and sulphur dioxide gas is formed
which is air pollutant. It also leads to the formation of acid rain which is harmful for crops and buildings made from marble.
How can sulphuric acid help in national economy?

Metals are very useful in our daily life. Aluminium powder is used in white paints. It is also used as a reducing agent. Alloys containing aluminium being light, are very useful. Utensils of aluminium are more popular than utensils of brass. Metals like silver, gold, iron, copper, zinc are very useful in our daily life.
(i) Which metal foils are used as wrappers for sweets, medicines, chapaties ties etc ?
(ii) Why are aluminium vessels preferred over copper and bronze vessels?
(iii) What value is associated for using aluminium?

Metals are very useful in our daily life. Aluminium powder is used in white paints. It is also used as a reducing agent. Alloys containing aluminium being light, are very useful. Utensils of aluminium are more popular than utensils of brass. Metals like silver, gold, iron, copper, zinc are very useful in our daily life.
Why are aluminium vessels preferred over copper and bronze vessels?

Metals are very useful in our daily life. Aluminium powder is used in white paints. It is also used as a reducing agent. Alloys containing aluminium being light, are very useful. Utensils of aluminium are more popular than utensils of brass. Metals like silver, gold, iron, copper, zinc are very useful in our daily life.
What value is associated for using aluminium?