Free s-Block and p-Block Elements MCQs with Answers

• A. 5-10
• B. 20-25
• C. 35-40
• D. 90

Explanation: Bleaching powder, also known as calcium hypochlorite (Ca(ClO)₂), typically contains a percentage of available chlorine in the range of…

• A. Cryolite
• B. Fluorspar
• C. Dolomite
• D. Both a and b

Explanation: Both Cryolite (Na₃AlF₆) and Fluorspar (CaF₂) are important ores of fluorine.

• A. Strong oxidizing agent
• B. Weak oxidizing agent
• C. Strong reducing agent
• D. Weak reducing agent

Explanation: Sulfur (S) acts as a strong reducing agent in the reaction with HI. This is because sulfur has a higher tendency to lose electrons (get…

• A. High ionization energy
• B. Low ionization energy
• C. Zero ionization Energy
• D. None of these

Explanation: Noble gases have a very high ionization energy. This is because their outermost electron shell is completely filled, making them very…

• A. F₂
• B. Cl₂
• C. Br₂
• D. I₂

Explanation: The oxidizing power of halogens decreases down the group. Fluorine (F₂) is the strongest oxidizing agent among the halogens, followed by…

• A. Chlorine
• B. Bromine
• C. Fluorine
• D. Iodine

Explanation: Teflon is a synthetic fluoropolymer, meaning it is a polymer made up of repeating units containing fluorine atoms.

• A. Iodine
• B. Bromine
• C. Chlorine
• D. Fluorine

Explanation: Iodine (I) has the largest atomic size among the given halogens. As atomic size increases, the outermost electrons are farther from the…

• A. Salt formers
• B. Rare earth elements
• C. Alkali metals
• D. Noble gases

Explanation: Halogens are known as salt formers because they react with metals to form salts.

• A. MnO2
• B. PbO2
• C. BaO2
• D. None of the above

Explanation: Hydrogen peroxide (H₂O₂) is formed by the reaction of an acid with a peroxide.

• A. 1 : 1
• B. 1 : 2
• C. 2 : 1
• D. 9 : 4

Explanation: The balanced chemical equations are Zn + H₂SO₄ → ZnSO₄ + H₂ and Zn + 2NaOH → Na₂ZnO₂ + H₂.

• A. Number of electrons
• B. Number of neutrons
• C. Number of paired electrons
• D. Number of protons

Explanation: Melting and boiling points generally increase with the number of electrons, because more electrons lead to stronger London dispersion (van…

• A. KI + HCl
• B. O3
• C. PbS
• D. Na2SO3

Explanation: Ozone (O₃) is a much stronger oxidizing agent than hydrogen peroxide (H₂O₂).

• A. HgS
• B. PbS
• C. NiS
• D. CuS

Explanation: Lead(II) sulfide (PbS) is a black solid. Hydrogen peroxide oxidizes it to lead(II) sulfate (PbSO₄), which is a white solid, via the…

• A. NaOH
• B. Mg(OH)2
• C. NH4OH
• D. All are equally strong

Explanation: Sodium hydroxide (NaOH) is the strongest base among the options because it is the hydroxide of a Group 1 alkali metal.

• A. CO + H2
• B. CO + N2
• C. CO + H2 + N2
• D. None of the above

Explanation: Semi-water gas is produced when a mixture of steam and air is passed over hot coke.

• A. NaH
• B. CaH2
• C. SrH2
• D. AsH3

Explanation: Covalent hydrides are formed when hydrogen bonds with nonmetals or metalloids.

• A. B2H6
• B. NH3
• C. H2O
• D. CH4

Explanation: Electron-precise hydrides have just enough electrons to form normal single bonds-no shortage, no extra lone pairs.

• A. Hydrogen can be fused to form helium
• B. Helium can be fused to form hydrogen
• C. Helium dissociate to form hydrogen
• D. None of these

Explanation: Under the extreme conditions of temperature and pressure found in the cores of stars, nuclear fusion occurs.

• A. Copper
• B. Zinc
• C. Iron
• D. Both b and c

Explanation: A metal will displace hydrogen from a dilute acid if it is more reactive than hydrogen (i.e., higher in the electrochemical series).

• A. Addition of ice cold H2SO4 on BaO2
• B. Addition of ice cold H2SO4 on PbO2
• C. Aerial oxidation of 2 ethyl anthraquinol
• D. Electrolysis of (NH4)2SO4 at a high current density

Explanation: Lead dioxide (PbO₂) is not a peroxide but a true oxide of lead in the +4 oxidation state.