Chapter 18

Iron loses its magnetic property at 1 (a) boiling point (b) melting point (c) \(1000 \mathrm{~K}\) (d) curie point

The purest form of iron is (a) pig iron (b) wrought iron (c) red iron (d) steel

Which of the follwoing reaction occurs in the combustion zone of the blast furnace during the extraction of iron? (a) \(\mathrm{CO}_{2}+\mathrm{C} \longrightarrow 2 \mathrm{CO}\) (b) \(\mathrm{CaO}+\mathrm{SiO}_{2} \longrightarrow \mathrm{CaSiO}_{3}\) (c) \(\mathrm{C}+\mathrm{O}_{2} \longrightarrow \mathrm{CO}_{2}\) (d) \(\mathrm{FeO}+\mathrm{CO} \longrightarrow \mathrm{Fe}+\mathrm{CO}_{2}\)

Which of the following is formed when ferrous oxalate is heated in the absence of air? (a) \(\mathrm{Fe}_{2} \mathrm{O}_{3}\) (b) \(\mathrm{Fe}_{3} \mathrm{O}_{4}\) (c) \(\mathrm{Fe}_{2} \mathrm{O}_{4}\) (d) \(\mathrm{FeO}\)

On igniting \(\mathrm{Fe}_{2} \mathrm{O}_{3}\) at 1673 (a) \(\mathrm{Fe}_{2} \mathrm{O}_{3}\) starts melting (b) Feo is formed (c) metallic iron is formed (d) both (b) and (c)

Ferric iron forms a prussian blue coloured precipitate with \(\mathrm{K}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]\), due to the formation of (a) \(\mathrm{Fe}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]_{3}\) (b) \(\mathrm{K}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]\) (c) \(\mathrm{K}_{3}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]\) (d) \(\mathrm{Fe}(\mathrm{CNS})_{3}\)

Thermite is a mixture of (a) \(\mathrm{Zn}+\mathrm{CaCO}_{3}\) (b) \(\mathrm{Mg} \mathrm{O}+\mathrm{Al}\) (c) \(\mathrm{Fe}_{3} \mathrm{O}_{4}+\mathrm{Al}\) (d) \(\mathrm{Zn}+\mathrm{P}_{2} \mathrm{O}_{5}\)

Cassiterite is concentrated by (a) hand picking (b) levigation (c) electromagnetic separation (d) Wilfley table method

Galena ore is concentrated by (a) gravity separation (b) froth flotation process (c) magnetic separation (d) roasting

Wolframite ore is separated from tinstone ore by the process of (a) smelting (b) calcination (c) roasting (d) electromagnetic

In the manufacture of iron from haematite, lime stone is added to act as an (a) slage (b) reducing agent (c) oxidizing agent (d) flux

Tin stone is contaminated with Wolframite. Which one of the following methods can be employed to dress the tin stone ore? (a) electromagnetic separation (b) levigation (c) roasting (d) floatation process

Identify the reaction that does not take place during the smelting process of copper extraction. (a) \(\mathrm{Cu}_{2} \mathrm{O}+\mathrm{FeS} \longrightarrow \mathrm{Cu}_{2} \mathrm{~S}+\mathrm{FeO}\) (b) \(\mathrm{FeO}+\mathrm{SiO}_{2} \longrightarrow \mathrm{FeSiO}_{3}\) (c) \(2 \mathrm{Cu}_{2} \mathrm{~S}+3 \mathrm{O}_{2} \longrightarrow 2 \mathrm{Cu}_{2} \mathrm{O}+2 \mathrm{SO}_{2} \uparrow\) (d) \(2 \mathrm{FeS}+3 \mathrm{O}_{2} \longrightarrow 2 \mathrm{FeO}+2 \mathrm{SO}_{2} \uparrow\)

Which of the following is obtained when \(\mathrm{Fe}\) reacts with dil \(\mathrm{HNO}_{3} ?\) (a) NO (b) \(\mathrm{N}_{2} \mathrm{O}\) (c) \(\mathrm{NO}_{2}\) (d) none of these

In the extraction of iron slag is produced which is (a) \(\mathrm{CaSiO}_{3}\) (b) \(\mathrm{FeSiO}_{3}\) (c) \(\mathrm{CO}\) (d) \(\mathrm{MgSiO}_{3}\)

The oxidation number of \(\mathrm{Fe}\) in \(\mathrm{Fe}_{3} \mathrm{O}_{4}\) is (a) \(+2\) (b) \(2 / 3\) (c) \(+3\) (d) \(8 / 3\)

Iron sulphide is heated in air to form \(\mathrm{A}\), an oxide of sulphur. A is dissolved in water to give an acid. The basicity of this acid is (a) zero (b) 1 (c) 2 (d) 3

Which of the following gives blood red colour with KCNS? (a) \(\mathrm{Al}^{3+}\) (b) \(\mathrm{Zn}^{2+}\) (c) \(\mathrm{Fe}^{3+}\) (d) \(\mathrm{Cu}^{2+}\)

The iron obtained from blast furnace is (a) soft iron (b) pig iron (c) steel (d) wrought iron

If steel is heated to a temperature well below where it becomes red hot and is then cooled slowly, the process is called (a) hardening (b) tempering (c) annealing (d) softening

The nature of an aqueous solution of \(\mathrm{FeCl}_{2}\) is (a) basic (b) acidic (c) amphoteric (d) neutral

The number of ions formed on dissolving one molecule of \(\mathrm{FeSO}_{4}\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4} \cdot 6 \mathrm{H}_{2} \mathrm{O}\) is (a) 6 (b) 5 (c) 4 (d) 3

Chromite ore can be given as (a) \(\mathrm{FeCr}_{2} \mathrm{O}_{7}\) (b) \(\mathrm{Cr}_{2} \mathrm{O}_{3}\) (c) \(\mathrm{FeCr}_{2} \mathrm{O}_{4}\) (d) \(\mathrm{Fe}_{3} \mathrm{O}_{4}\)

Wrought iron, pig iron and steel differ in properties due to (a) carbon content (b) softness (c) conductivity (d) malleability

Which of the following is not an ore of iron? (a) magnetite (b) limonite (c) cassiterite (d) haematite

Corrosion is basically a (a) interaction (b) union between light metal and heavy metal (c) electrochemical phenomenon (d) altered reaction in presence of water

Ferrosilicon is used in the steel industry as (a) cutting tool (b) alloying agent (c) flux (d) a reducing agent

The ore which contains copper and iron both is (a) cuprite (b) chalcocite (c) chalcopyrite (d) malachite

In the blast furnace, iron oxide is reduced by (a) silica (b) carbon (c) hot blast of air (d) carbon monoxide

The percentage of silver in german silver, is (a) \(0 \%\) (b) \(10 \%\) (c) \(2.5 \%\) (d) \(4.5 \%\)

Which of the following alloy contains \(\mathrm{Cu}\) and \(\mathrm{Zn}\) ? (a) bell metal (b) aluminium bronze (c) brass (d) bronze

Bell metal is an alloy of (a) \(\mathrm{Cu}+\mathrm{Sn}\) (b) \(\mathrm{Cu}+\mathrm{Zn}\) (c) \(\mathrm{Cu}+\mathrm{Ni}\) (d) \(\mathrm{Cu}+\mathrm{Pb}\)

An extremely hot copper wire reacts with steam to give (a) \(\mathrm{Cu}_{2} \mathrm{O}\) (b) \(\mathrm{CuO}_{2}\) (c) \(\mathrm{Cu}_{2} \mathrm{O}_{2}\) (d) \(\mathrm{CuO}\)

Which of the following is produced, when copper reacts with chlorine? (a) \(\mathrm{CuCl}_{4}\) (b) \(\mathrm{Cu}_{2} \mathrm{Cl}\) (c) \(\mathrm{Cu}_{2} \mathrm{Cl}_{2}^{4}\) (d) \(\mathrm{CuCl}_{2}\)

Which of the following metal does not react with the solution of copper sulphate? (a) \(\mathrm{Fe}\) (b) \(\mathrm{Zn}\) (c) \(\mathrm{Ag}\) (d) \(\mathrm{Mg}\)

Which of the following metal is present in brass, bronze and german silver? (a) \(\mathrm{Mg}\) (b) \(\mathrm{Cu}\) (c) \(\mathrm{Al}\) (d) \(\mathrm{Na}\)

Which of the following gas is evolved when cupric sulphide (CuS) is dissolved in dilute hydrochloric acid \((\mathrm{HCl}) ?\) (a) \(\underline{\mathrm{S}}\) (b) \(\mathrm{Cl}_{2}\) (c) \(\mathrm{H}_{2} \mathrm{~S}\) (d) \(\mathrm{H}_{2}\)

On strongly heating copper nitrate, we get (a) copper metal (b) cuprous oxide (c) cupric oxide (d) copper sulphate

What is formed when \(\mathrm{H}_{2} \mathrm{~S}\) is passed through acidified solution of \(\mathrm{CuSO}_{4} ?\) (a) \(\mathrm{CuSO}_{4}\) (b) \(\mathrm{CuS}\) (c) \(\mathrm{CuHSO}_{4}\) (d) \(\mathrm{Cu}_{2} \mathrm{~S}\)

What is produced when cuprous oxide reacts with HCl? (a) \(\mathrm{CuCl}\) (b) \(\mathrm{CuO}\) (c) \(\mathrm{HCuCl}_{2}\) (d) \(\mathrm{CuCl}_{2}\)

\(\mathrm{SO}_{2}\) gas reacts with a solution of \(\mathrm{CuSO}_{4}\) and \(\mathrm{KCN}\) to produce (a) a mixture of \(\mathrm{Cu}(\mathrm{CNS})_{2}\) and \(\mathrm{H}_{2} \mathrm{SO}_{4}\) (b) a complex, \(\left[\mathrm{Cu}(\mathrm{CNS})_{4}\right] \mathrm{SO}_{4}\) (c) a white precipitate of \(\mathrm{CuCNS}\) (d) both (a) and (c)

Cuprous ore among the following is (a) cuprite (b) malachite (c) chalcopyrites (d) azurite

The percentage of copper, tin and zinc metals present in 'Gun metal' respectively are (a) \(88,2,10\) (b) \(88,10,2\) (c) \(80,20,0\) (d) \(80,0,20\)

When metallic copper comes in contact with moisture, a green powdery/pasty coating can be seen over it. This is chemically known as (a) copper carbonate-copper sulphate (b) copper sulphate-copper sulphide (c) copper carbonate copper hydroxide (d) copper sulphide-copper carbonate

Which of the following metal is found in gun metal, monel metal and constantan alloys? (a) \(\mathrm{Cu}\) (b) \(\mathrm{Fe}\) (c) \(\mathrm{Hg}\) (d) \(\mathrm{Zn}\)

Lunar caustic is (a) \(\mathrm{NaOH}\) (b) \(\mathrm{NaNO}_{3}\) (c) \(\mathrm{AgNO}_{3}\) (d) \(\mathrm{Ag}_{2} \mathrm{SO}_{4}\)

Silver is present in (a) galena (b) magnetite (c) dolomite (d) limonite

Cyanide process is used in the extraction of (a) \(\mathrm{Cu}\) (b) \(\mathrm{Al}\) (c) \(\mathrm{Zn}\) (d) \(\mathrm{Ag}\)

\(\mathrm{Kl}\) and \(\mathrm{CuSO}_{4}\) solution when mixed gives (a) \(\mathrm{K}_{2} \mathrm{SO}_{4}+\mathrm{Cu}_{2} \mathrm{I}_{2}+\mathrm{I}_{2}\) (b) \(\mathrm{Cu}_{2} \mathrm{I}_{2}+\mathrm{K}_{2} \mathrm{SO}_{4}^{2}\) (c) \(\mathrm{CuI}_{2}+\mathrm{K}_{2} \mathrm{SO}_{4}\) (d) \(\mathrm{K}_{2} \mathrm{SO}_{4}+\mathrm{CuI}_{2}^{2}+\mathrm{I}_{2}\)

Which of the following is used in the extraction of silver? (a) \(\mathrm{NaCN}\) (b) \(\mathrm{Na}_{2} \mathrm{SO}_{4}\) (c) \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) (d) \(\mathrm{NaCl}\)