MCQ 11 Mark
The atomic numbers of four elements $\ce{A, B, C}$ and $\ce{D}$ are $6, 8, 10$ and $12$ respectively. The two elements which can react to form ionic bonds $($or ionic compound$)$ are:
- A
$A$ and $D$
- B
$B$ and $C$
- C
$A$ and $C$
- ✓
$B$ and $D$
AnswerCorrect option: D. $B$ and $D$
Element $B$ has the electronic configuration of $2, 6.$ It requires $2$ electrons to complete its octet. On the other hand, element $D$ has the electronic configuration of $2, 8, 2.$ It requires to release $2$ electrons to complete its octet.
Thus, both atoms react to form ionic bonds by transfer of electrons.
View full question & answer→MCQ 21 Mark
An important ore of zinc metal is:
AnswerCalamine is an ore of zinc and the compound is zinc carbonate $\ce{(ZnCO_3)}$.
View full question & answer→MCQ 31 Mark
The number of protons in one atom of an element $X$ is $8$. What will be the number of electrons in its ion $x^{2-}$
AnswerNumber of protons is equal to the number of electrons in an atom. It is given that one atom of an element $X$ contains $8$ electrons.
Therefore, number of electrons in its ion $x^{2-}=10+2=12$
View full question & answer→MCQ 41 Mark
Which of the following non$-$metal is a liquid?
AnswerBromine is the non$-$metal that is a liquid.
View full question & answer→MCQ 51 Mark
The noble gas having only two electrons in its valence shell is:
AnswerAtomic number of helium is $2.$ It contains $2$ electrons in its atom.
View full question & answer→MCQ 61 Mark
In stainless steel alloy, iron metal is mixed with:
- A
$Cu$ and $Cr$
- ✓
$Cr$ and $Ni$
- C
$Cr$ and $Sn$
- D
$Cu$ and $Ni$
AnswerCorrect option: B. $Cr$ and $Ni$
Stainless steel is an alloy of iron, chromium and nickel. It is extremely strong and tough and does not corrode at all.
View full question & answer→MCQ 71 Mark
Which of the following is an ore of mercury metal?
AnswerCinnabar is an important ore of mercury. Its compound is mercury $(II)$ sulphide $\ce{(HgS)}.$
View full question & answer→MCQ 81 Mark
Element $X$ reacts with element $Y$ to form a compound $Z.$ During the formation of compound $Z,$ atoms of $X$ lose one electron each whereas atoms of $Y$ gain one electron each. Which of the following property is not shown by compound $Z?$
- A
- ✓
- C
- D
Conduction of electricity in molten state.
AnswerCompound $Z$ is an ionic compound formed by transfer of electrons. Ionic compounds have high melting points.
View full question & answer→MCQ 91 Mark
The two metals which can be extracted just by heating their sulphides in air are:
AnswerBoth mercury and copper are less reactive metals and are placed low in the reactivity series.
Hence, they can be extracted by heating their sulphides in air and further reducing their oxides by heating.
View full question & answer→MCQ 101 Mark
An ore of manganese metal is:
AnswerPyrolusite is an ore of manganese and the compound is manganese dioxide $\ce{(MnO_2)}$.
View full question & answer→MCQ 111 Mark
A covalent molecule having a double bond between its atoms is:
AnswerIn an oxygen molecule, each oxygen atom shares its $2$ electrons to complete its octet and forms double covalent bond between them.
View full question & answer→MCQ 121 Mark
Calamine ore can be converted into zinc oxide by the process of:
AnswerCalamine $(\ce{ZnCO_3}$, zinc carbonate$)$ is a carbonate ore of zinc. Carbonate ores are converted to metal oxides by calcination $($heating in the absence of air$)$. When calamine ore $($zinc carbonate$)$ is heated in the absence of air, it is converted into zinc oxide.
View full question & answer→MCQ 131 Mark
Which of the following metals can be obtained from haematite ore?
AnswerIron can be obtained from hematite ore. Hematite ore contains the compound iron $(III)$ oxide $\ce{(Fe_2O_3)}$.
View full question & answer→MCQ 141 Mark
The metal which can be extracted simply by heating the cinnabar ore in air is:
AnswerMercury is a low reactive metal. Thus, it can be extracted from its ore cinnabar, $\ce{HgS},$ by heating it in air.
View full question & answer→MCQ 151 Mark
Rock salt is an ore of one of the following metals. This metal is:
AnswerRock salt is a chloride ore of sodium. The name of the compound in the ore is sodium chloride with chemical formula $\ce{NaCl}.$
View full question & answer→MCQ 161 Mark
The rechargeable battery used in a mobile phone hand set is usually:
AnswerBecause lithium ion is a good conductor of electricity.
View full question & answer→MCQ 171 Mark
An element $E$ reacts with water to form a solution which turns phenolphthalein solution pink. The element $E$ is most likely to be:
AnswerCalcium is the metal that can react with water to form calcium hydroxide, which is basic in nature.
Hence it turns phenolphthalein solution pink.
View full question & answer→MCQ 181 Mark
One of the following contains a double bond as well as single bonds. This is:
- A
$CO_2$
- B
$O_2$
- ✓
$C_2H_4$
- D
$C_2H_2$
AnswerCorrect option: C. $C_2H_4$
An ethene molecule $\ce{(C_2H_4)}$ contains one double bond between two carbon atoms and four single bonds between carbon and hydrogen atoms.
View full question & answer→MCQ 191 Mark
The elements whose oxides can turn litmus solution blue are:
AnswerPotassium and magnesium are metals whose oxides are basic in nature. These oxides turn red litmus solution to blue.
View full question & answer→MCQ 201 Mark
An element $X$ reacts with hydrogen, when heated, to form a covalent hydride $\ce{H_2X}$. If $\ce{H_2X}$ has a smell of rotten eggs, the element $X$ is likely to be:
AnswerBecause sulphur reacts with hydrogen to form a covalent hydride, $\ce{H_2S}$ that has the smell of rotten eggs.
View full question & answer→MCQ 211 Mark
A common metal which is highly resistant to corrosion is:
AnswerAluminium is resistant to corrosion due to the formation of a thin oxide layer $($aluminium oxide or $\ce{Al_2O_3).}$ This prevents further corrosion by creating a strong protective layer over the surface of the metal.
View full question & answer→MCQ 221 Mark
The electronic configurations of three elements $X, Y$ and $Z$ are:
$X : 2$
$Y : 2, 8, 7$
$Z : 2, 8, 2$
Which of the following is correct regarding these elements?
AnswerCorrect option: D. $Y$ is a non$-$metal and $Z$ is a metal.
Element $Y$ has $1$ less electron to complete its octet which is a property of non$-$metals. On the other hand, element $Z$ has $2$ extra electrons to become stabilised which is a property of metals.
View full question & answer→MCQ 231 Mark
Which of the following alloys contains mercury as one of the constituents?
AnswerGenerally, alloys containing mercury as one of its constituents are known as amalgam. Zinc amalgam is an alloy of zinc and liquid mercury.
View full question & answer→MCQ 241 Mark
Which of the following pair of metals exists in their native state in nature?
- A
$Ag$ and $Hg.$
- B
$Ag$ and $Zn.$
- C
$Au$ and $Hg.$
- ✓
$Au$ and $Ag.$
AnswerCorrect option: D. $Au$ and $Ag.$
Gold $(Au)$ and silver $(Ag)$ are highly non$-$reactive. Hence, they are available in native state in nature and do not react with oxygen or any other element in the atmosphere.
View full question & answer→MCQ 251 Mark
The elements whose oxides can turn litmus solution red are:
AnswerPhosphorus and sulphur are non$-$metals whose oxides are acidic in nature. These oxides turn blue litmus solution to red.
View full question & answer→MCQ 261 Mark
Which of the following has a triple bond as well as single bonds?
AnswerAn ethyne molecule $(H - C ≡ C - H)$ contains a triple bond between two carbon atoms and two single bonds between carbon and hydrogen atoms.
View full question & answer→MCQ 271 Mark
Zinc oxide is a metal oxide. Which of the following term best describes the nature of zinc oxide:
AnswerZinc oxide can react with both acids and bases to form salt and water.
View full question & answer→MCQ 281 Mark
A sulphide ore is converted into metal oxide by the process of:
AnswerSulphide ores are transformed into oxides by the process of roasting. In this process, concentrated ore is heated in the presence of surplus air. Example: Zinc blende, $\ce{ZnS},$ a sulphide ore of zinc, is roasted in the presence of air. On roasting, zinc sulphide gets transformed into zinc oxide.
View full question & answer→MCQ 291 Mark
The major ore of aluminium is known as:
AnswerBauxite is one of the major ores of aluminium. Its compound is aluminium oxide $\ce{(Al_2O_3.2H_2O)}$.
View full question & answer→MCQ 301 Mark
Which one of the following property is generally not exhibited by ionic compounds?
- A
- ✓
Electrical conductivity in solid state.
- C
High melting and boiling points.
- D
Electrical conductivity in molten state.
AnswerCorrect option: B. Electrical conductivity in solid state.
Because ionic compounds conduct electricity only in molten state or when dissolved in water to form aqueous solution.
View full question & answer→MCQ 311 Mark
Which one of the following four metals would be displaced from the solution of its salt by the other three metals?
Answer$Ag$ will be replaced from the solution of its salt by the other three metals.
View full question & answer→MCQ 321 Mark
The metal which is always present in an amalgam is:
AnswerAn amalgam is an alloy of mercury with one or more metals. The combination of sodium with liquid mercury is called sodium amalgam. Amalgam of mercury with gold, silver or zinc is widely used for dental fillings.
View full question & answer→MCQ 331 Mark
An element $X$ forms two oxides $\ce{XO}$ and $\ce{XO_2}$. The oxide $\ce{XO}$ is neutral but $\ce{XO_2}$ is acidic in nature. The element $X$ is most likely to be:
AnswerCarbon forms two oxides, $\ce{CO}$ and $\ce{CO_2}$. The oxide $\ce{CO}$ is neutral and $\ce{CO_2}$ is acidic in nature.
View full question & answer→MCQ 341 Mark
The metals which can produce amphoteric oxides are:
AnswerBoth aluminium and zinc oxides react with acids and bases to form salt and water.
View full question & answer→MCQ 351 Mark
- A
$Cu$ and $Sn.$
- B
$Cu$ and $Pb.$
- C
$Pb$ and $Sn.$
- ✓
$Zn$ and $Cu.$
AnswerCorrect option: D. $Zn$ and $Cu.$
Brass is an alloy of copper and zinc. It comprises of $80$ percent copper and $20$ percent zinc.
View full question & answer→MCQ 361 Mark
Out of $\ce{KCl, HCl, CCl_4}$ and $\ce{NaCl}$, the compounds which are not ionic are:
- A
$\ce{KCl}$ and $\ce{HCl}$.
- ✓
$\ce{HCl}$ and $\ce{CCl_4}$.
- C
$\ce{CCl_4}$ and $\ce{NaCl}$.
- D
$\ce{KCl}$ and $\ce{CCl_4}$.
AnswerCorrect option: B. $\ce{HCl}$ and $\ce{CCl_4}$.
Both these compounds are formed by sharing of electrons and hence, they form covalent bonds and not ionic bonds.
View full question & answer→MCQ 371 Mark
During galvanisation, iron metal is given a thin coating of one of the following metals. This metal is:
AnswerGalvanisation is a process that involves dipping of iron objects into melted zinc. This gives a thin coating of zinc layer on the iron object that protects it from corrosion. Zinc, being a highly reactive metal, forms a thin layer of zinc oxide, which prevents iron from getting exposed to the atmospheric air.
View full question & answer→MCQ 381 Mark
The solution of one of the following compounds will not conduct electricity. This compounds is:
- A
$\ce{NaCl}$
- ✓
$\ce{CCl_4}$
- C
$\ce{MgCl_2}$
- D
$\ce{CaCl_2}$
AnswerCorrect option: B. $\ce{CCl_4}$
Because it is a covalent compound.
View full question & answer→MCQ 391 Mark
The metal which is always present in an amalgam is:
AnswerAn amalgam is an alloy of mercury with one or more metals. The combination of sodium with liquid mercury is called sodium amalgam. Amalgam of mercury with gold, silver or zinc is widely used for dental fillings.
View full question & answer→MCQ 401 Mark
The metal which can be extracted from pyrolusite ore is:
AnswerManganese is extracted from its oxide ore, pyrolusite. The name of the compound in the ore is manganese dioxide having chemical formula $\ce{MnO_2}$.
View full question & answer→MCQ 411 Mark
The two metals which are extracted by means of electrolytic reduction of their molten salts are:
AnswerThis is because magnesium and aluminium are highly reactive metals and are placed high in the reactivity series. This is also due to the fact that their oxides are very stable and cannot be reduced easily.
View full question & answer→MCQ 421 Mark
Which of the following is an iron ore?
AnswerHaematite is an iron ore and the compound is iron $(III)$ oxide $\ce{(Fe_2O_3)}$.
View full question & answer→MCQ 431 Mark
Which of the following metal exists in the liquid state?
AnswerMercury $(Hg)$ is the metal that exists in liquid state at room temperature.
View full question & answer→MCQ 441 Mark
A basic oxide will be formed by the element:
AnswerBecause $K$ is a metal, its oxide $\ce{K_2O}$ is a basic oxide.
View full question & answer→MCQ 451 Mark
An element is soft and can be cut with a knife. It is very reactive and cannot be kept open in the air. It reacts vigorously with water. The element is most likely to be:
Answer$Na$ is soft and can be cut with a knife. It is very reactive and cannot be kept in open air. It reacts vigorously with water.
View full question & answer→MCQ 461 Mark
Zinc blende ore can be converted into zinc oxide by the process of:
MCQ 471 Mark
The atomic number of an element $X$ is $19$. The number of electrons in its ion $X^+$ will be:
AnswerBecause $X^+$ ion contains one less electron than $X$.
View full question & answer→MCQ 481 Mark
Out of the following oxides, the amphoteric oxide is:
- A
$\ce{Fe_2O_3}$
- ✓
$\ce{Al_2O_3}$
- C
$\ce{P_2O_5}$
- D
$\ce{N_2O}$
AnswerCorrect option: B. $\ce{Al_2O_3}$
$\ce{Al_2O_3}$ can react with acids as well as bases to form salt and water.
View full question & answer→MCQ 491 Mark
The electrons present in the valence shell of a noble gas atom can be:
- A
$8$ only.
- B
$2$ only.
- ✓
$8$ or $2.$
- D
$8$ or $4.$
AnswerCorrect option: C. $8$ or $2.$
Helium is the only noble gas that has $2$ electrons in its valence shell. Other noble gases have $8$ electrons in their valence shells.
View full question & answer→MCQ 501 Mark
The atomic numbers of four elements $P, Q, R$ and $S$ are $6, 10, 12$ and $17$ respectively. Which two elements can combine to form a covalent compound?
- A
$P$ and $R$
- B
$Q$ and $S$
- ✓
$P$ and $S$
- D
$R$ and $S$
AnswerCorrect option: C. $P$ and $S$
Element $P$ needs $4$ electrons to complete its octet. They can be shared with element $S,$ which needs only $1$ electron to complete its octet.
View full question & answer→MCQ 511 Mark
Calamine ore can be used to extract one of the following metals. This metal is:
AnswerCalamine is an ore of zinc and its compound is zinc carbonate $\ce{(ZnCO_3).}$
View full question & answer→MCQ 521 Mark
Which of the following reactants are used to carry out the thermite reaction required for welding the broken railway tracks?
- A
$\ce{Al_2O_3 + Fe.}$
- B
$\ce{MnO_2 + Al.}$
- ✓
$\ce{Fe_2O_3 + Al.}$
- D
$\ce{Cu_2O + Fe.}$
AnswerCorrect option: C. $\ce{Fe_2O_3 + Al.}$
In this thermite reaction, iron $(III)$ oxide and aluminium powder are combined and heated. Iron oxide gets reduced to iron by the action of reducing agent aluminium and produces excess heat. The molten iron produced is poured in the middle of the broken pieces of irons that are fixed mutually.
View full question & answer→MCQ 531 Mark
If the number of protons in one atom of an element $Y$ is $20$, then the number of electrons in its ion $Y^{2^+}$ will be:
AnswerNumber of protons is equal to the number of electrons in an atom. It is given that an atom of an element $Y$ contains $20$ electrons.
Therefore, number of electrons in its ion $Y^{2^+}$ is $18(20 − 2$).
View full question & answer→MCQ 541 Mark
"Is malleable and ductile". This best describes:
AnswerBecause malleability and ductility are the properties of metals.
View full question & answer→MCQ 551 Mark
Out of aluminium, copper, calcium and tin, the most reactive metal is:
AnswerCalcium lies above the other three metals in reactivity series.
View full question & answer→MCQ 561 Mark
The atomic number of an element $X$ is $16$. The symbol of ion formed by an atom of this element will be:
- A
$X^{2^+}$
- B
$X^{3^+}$
- ✓
$X^{2^−}$
- D
$X^−$
AnswerCorrect option: C. $X^{2^−}$
Element $X$ needs $2$ electrons to complete its octet. Therefore, it forms $X^{2^−}$ anion.
View full question & answer→MCQ 571 Mark
Which of the following pair of reactants can undergo a displacement reaction under appropriate conditions?
- A
$\ce{MgSO_4 + Fe}.$
- B
$\ce{ZnSO_4 + Fe.}$
- C
$\ce{MgSO_4 + Pb.}$
- ✓
$\ce{CuSO_4 + Fe.}$
AnswerCorrect option: D. $\ce{CuSO_4 + Fe.}$
Iron $(Fe)$ is a more reactive metal than copper, which can displace copper from copper sulphate.
View full question & answer→MCQ 581 Mark
The number of protons in the nucleus of one atom of an element $Y$ is $5$. The symbol of ion formed by an atom of this element will be:
- A
$Y^{3^−}$
- B
$Y^{2^+}$
- C
$Y^{2−}$
- ✓
$Y^{3^+}$
AnswerCorrect option: D. $Y^{3^+}$
Number of protons is equal to number of electrons in an atom.
Hence, electronic configuration of element $Y$ is $2, 3$.
Thus, it becomes stabilised by donating its $3$ electrons to form $Y^{3^+}$.
View full question & answer→MCQ 591 Mark
During the refining of an impure metal by electrolysis, the pure metal is a deposited:
- ✓
- B
On the walls of electrolytic tank.
- C
- D
At the bottom of electrolytic tank.
AnswerIn electrolytic refining, pure metal is always deposited at the cathode. The impure metal is made anode $($positive terminal$)$ and a thin rod of pure metal is made cathode $($negative terminal$).$ The salt of the metal is made electrolyte in the cell. When electricity passed through the cell, the impure metal dissolves in the electrolytic solution. The pure metal from the electrolytic solutions moves and gets deposited at the cathode.
View full question & answer→MCQ 601 Mark
You are given a solution of $\ce{AgNO_3}$. Which of the following do you think cannot displace $Ag$ from $\ce{AgNO_3}$ solution?
AnswerBecause gold is less reactive than silver. The other metals are more reactive than silver and can displace it from silver nitrate solution.
View full question & answer→MCQ 611 Mark
A metal less reactive and another metal more reactive than hydrogen are:
AnswerCopper lies below hydrogen and tin lies above hydrogen in the reactivity series of metals.
View full question & answer→MCQ 621 Mark
Manganese metal is extracted from manganese dioxide by a reduction process by making use of:
AnswerThere are some metals that cannot be satisfactorily reduced by carbon. In such cases, aluminium is used as reducing agent, e.g., manganese.
View full question & answer→MCQ 631 Mark
An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be:
AnswerCalcium reacts with oxygen to form calcium oxide with a high melting point. This compound is also soluble in water.
View full question & answer→MCQ 641 Mark
One of the following is not a neutral oxide. This is:
- A
$\ce{CO}$
- B
$\ce{H_2O}$
- C
$\ce{N_2O}$
- ✓
$\ce{Na_2O}$
AnswerCorrect option: D. $\ce{Na_2O}$
Because $\ce{Na_2O}$ is a metal oxide that is basic in nature.
View full question & answer→MCQ 651 Mark
An acidic oxide is produced by the element:
AnswerBecause $\ce{C}$ is a non$-$metal, its oxide $\ce{CO_2}$ is an acidic oxide.
View full question & answer→MCQ 661 Mark
If copper is kept exposed to damp air for a considerable time, it gets a green coating on its surface. This is due to the formation of:
- A
Hydrated copper sulphate.
- B
- ✓
- D
AnswerCopper reacts slowly with water and carbon dioxide in the atmosphere to form copper carbonate. This gives a green colour coating to its surface.
View full question & answer→MCQ 671 Mark
The atomic number of an element $Y$ is $17$. The number of electrons in its ion $Y^−$ will be:
AnswerAnion $Y^−$ has one more electron than its neutral atom. $Y$ atom has $17$ electrons and therefore, in $Y^−$, number of electrons will be $18(17 + 1)$.
View full question & answer→MCQ 681 Mark
The articles made of silver metal become dark on prolonged exposure to air. This is due to the formation of a layer of its:
AnswerSilver reacts with hydrogen sulphide gas in the air and forms a think black layer of silver sulphide $\ce{(Ag_2S)}$ on it. Silver jewellery or ornaments become dull because of the formation of silver sulphide coating on their surfaces.
View full question & answer→MCQ 691 Mark
The metal which can be extracted from the bauxite ore is:
AnswerAluminium can be extracted from bauxite. Bauxite is an ore of aluminium and the compound is aluminium oxide $\ce{(Al_2O_3.2H_2O)}$.
View full question & answer→MCQ 701 Mark
Which of the following alloys contains a non$-$metal as one of the constituents?
AnswerSteel is an alloy that contains a non$-$metal carbon as one of its constituents. It consists of iron with carbon $(0.1$ to $1.5\%).$
View full question & answer→MCQ 711 Mark
One of the following compounds is not ionic in nature. This compound is:
AnswerIt is a covalent compound.
View full question & answer→MCQ 721 Mark
Which of the following metals are extracted by the electrolysis of their molten chlorides?
- A
$Na$ and $Hg.$
- B
$Hg$ and $Mg.$
- ✓
$Na$ and $Mg.$
- D
$Cu$ and $Fe.$
AnswerCorrect option: C. $Na$ and $Mg.$
Sodium $(Na)$ and magnesium $( Mg )$ are highly reactive metals. They are not easily reduced by carbon and aluminium. Thus, they are extracted by electrolytic reduction or electrolysis of their molten chlorides $($sodium chloride, $\ce{NaCl}$ , and magnesium chloride, $\ce{MgCl _2}).$
View full question & answer→MCQ 731 Mark
The elements whose oxides can turn phenolphthalein solution pink are:
- ✓
$Na$ and $K.$
- B
$K$ and $C.$
- C
$Na$ and $S.$
- D
$K$ and $P.$
AnswerCorrect option: A. $Na$ and $K.$
Because $Na$ and $K$ are metals whose oxides are basic in nature, which can turn phenolphthalein solution pink.
View full question & answer→MCQ 741 Mark
The molecules having triple bond in them are:
- A
- B
Carbon dioxide and ammonia.
- C
- ✓
AnswerIn a nitrogen molecule, each nitrogen atom shares its $3$ electrons to form a triple bond among them. In an ethyne molecule, each carbon atom shares $3$ electrons to form a triple bond among them.
View full question & answer→MCQ 751 Mark
The least reactive metal among the following is:
AnswerBecause silver lies below other metals in the reactivity series.
View full question & answer→