Properties & Uses of Aluminium

Q. explain thermite reaction . Give example mention its uses

Q.

Arrange the metals in the decreasing order of their abundance in the earth's crust. [1 MARK]
Iron, potassium, calcium, aluminium, sodium, magnesium

Q. What is aluminothermy and why it has to be done?

Q.

Name the following:

Raw materials used in the preparation of ammonia.

Q. Lanthanides and actinides resemble in

1. Ionization energy
2. Formation of complexes

3. Oxidation state

4. Electronic configuration

Q.

Name the gas in the following:
The gas produced when excess ammonia reacts with chlorine.

Q. name a chemical used ffor dissolving al2o3.In which state of subdivision is the chemical used.

Q.

The chemical formula of magnet…..?

Q. Which of the given metals exhibits both reactions (a) as well as (b)?

(a) Metal + Oxygen $\to$ Metal oxide

(b) Metal + Cold water or hot water or steam $\to$ Metal hydroxide + Hydrogen

1. Magnesium (Mg), iron (Fe), sodium (Na), and copper (Cu)
2. Magnesium (Mg), zinc (Zn), platinum (Pt), and gold (Au)
3. Sodium (Na), potassium (K), magnesium (Mg) and calcium (Ca)
4. Copper (Cu), magnesium (Mg), gold (Au), and sodium (Na)

Q.

Zinc oxide and Aluminum oxide are ___ oxides.

Q.

Rewrite the following sentences correctly-

Zinc is less reactive than Hydrogen.

Q.

A component of water gas is used in the manufacture of ammonia.

1. True
2. False

Q.

why does hydrogen has a ambigues position ??

Q.

What happens when a base reacts with a metal?

1. Brisk effervescence occurs.

2. Milkiness is observed.

3. Gas formed burns with a pop sound.

4. A loud sound is produced.

Q.

Which metals are obtained by electrolytic reduction?

Q.

During the electrolytic extraction of Aluminium, purified alumina is mixed with $N{a}_3$ $Al{F}_6$ and $Ca{F}_2$. Why?

1. They increase the conductivity

2. They increase the Melting point of the mix

3. They decrease the conductivity

4. They decrease the Melting Point of the mix

Q.

Hydrogen cannot be produced from alkalis by chemical reaction.

1. True
2. False

Q. Which among the following is the softest metal?

1. Silver
2. Iron
3. Aluminium
4. Platinum

Q. Aluminium occurs in combined state whereas gold is found in free state. Why ?

Q. Which of the following metals cannot be obtained by reduction of its metal oxide by aluminium?

1. $Mn$
2. $Fe$
3. $Mg$
4. $Cr$

Q.

Assertion: Nitriding is the process of heating steel in presence of $N_2$ to convert it completely into iron nitride.

Reason: The surface of steel becomes hard after nitriding process

1. Both assertion and reason are correct and the reason is correct expansion to assertion

2. Both assertion and reason are correct but reason is not the correct expansion of assertion

3. Assertion is correct but reason are wrong

4. Assertion is incorrect but reason is correct

5. Both assertion and reason are wrong

Q.

When chlorine reacts with ammonia , it is reduced to X, which further combines with excess of ammonia to form Y. Name this Y.

1. H₂

2. HCl

3. NH₄Cl

4. NCl₃

Q. Alnico is an alloy used to make permanent magnets.
(a) Which is the metal present in Alnico in addition to iron, nickel and cobalt?
(b) Compounds in the process of extraction of aluminium are given:
$A{l}_2{O}_3\to Al(OH{)}_3\to N{a}_{3}Al{O}_3\to A{l}_2{O}_3.2H_{2}O$
If there is any mistake in the order of the compounds, write them in the correct order.
(c) "To extract $Al$ from its ore, carbon is not used as a reducing agent". Justify the statement.

Q.

Zone refining is a method to obtain:

1. Ultrapure Al

2. Moderately pure metals

3. ultrapure oxides

4. Ultrapure metals

Q.

The most abundant metal present in the Earth's crust is ____.

1. aluminium

2. iron

3. oxygen

4. copper

Q. Which of the following metals is obtained by electrolytic reduction process?

1. $Fe$
2. $Cu$
3. $Ag$
4. $Al$

Q. During extraction of aluminium from bauxite:

1. the concentration of ore is done by gravity separation method
2. molten mixture of aluminium oxide, cryolite or fluorspar is electrolysed
3. impure aluminium is defined by liquation
4. molten aluminium is obtained at cathode while fluorine is liberated at anode

Q. Assertion :In thermite welding, aluminium powder and $F{e}_2{O}_3$ are used. Reason: Aluminium powder is a strong reducing agent.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. The following questions are relevant to the extraction of aluminium:
Give a balanced chemical equation for the above reaction?

Q. What is aluminothermy and why it has to be done?