All Free Chemistry MCQs with Answers

• A. 72 pm
• B. 95 pm
• C. 136 pm
• D. 157 pm

Explanation: The atomic radius of fluorine is 72pm, but when an electron is added, the affective nuclear charge decreases so the ionic radius of an…

• A. 500 °C
• B. 200 °C
• C. -10 °C
• D. 15°C

Explanation: Reactant is present in aqua state (liquid) for the given options it is only possible at 15 degrees

• A. Cl2
• B. Br2
• C. I2
• D. F2

Explanation: The correct answer is I2. Among the halogen molecules, iodine (I2) has the weakest bond due to its large atomic size, which leads to…

• A. Sulphur (III) oxide
• B. Sulphur dioxide
• C. Iron pyrite
• D. Disulphur dichloride

Explanation: An anhydride is a compound that, when combined with water, forms an acid or base.When SO₂ reacts with water, it forms sulfurous acid…

• A. Strong electronegativity
• B. Strong attractive forces
• C. Increment in size
• D. High Ionization Energy

Explanation: Generally the melting point of the metals decreases down the group. This is because as the metal ions get larger the distance between the…

• A. Addition of a new shell
• B. Increase in nuclear charge
• C. High Ionization Energy
• D. Decrease in nuclear charge

Explanation: Across a period, effective nuclear charge increases as electron shielding remains constant.

• A. Krypton
• B. Argon
• C. Helium
• D. Neon

Explanation: Argon gas is an inert gas used in electric bulbs to prevent corrosion of its tungsten filament.

• A. HClaq
• B. KOHaq
• C. Steam
• D. SO3

Explanation: SiO2 is an acidic oxide and reacts with strong bases. Among the given options, it will react with hot, concentrated KOH(aq) due to the…

• A. Ionic bond
• B. Covalent bond
• C. Co-ordinate covalent bond
• D. Metallic bond

Explanation: The inert pair effect is the effect of the s-orbitals in which they do not participate to make bonds with other molecules because the…

• A. HI
• B. HF
• C. HBr
• D. All of the above

Explanation: HI is the strongest reducing agent. The compounds having low dissociation energy are a stronger reducing agent than the others having high…

• A. Ca(NO3)2 solution
• B. Ba(NO3)2 solution
• C. K2CO3 solution
• D. All turned milky

Explanation: When sulfuric acid is added to calcium nitrate, calcium sulfate is produced, which is slightly soluble and often forms a fine precipitate…

• A. NO
• B. 𝑆𝑂3
• C. 𝑁𝑂−3
• D. 𝑁𝑂2

Explanation: Nitrogen dioxide absorbs radiation in the ultraviolet (UV) and visible (vis) regions due to the electron transitions within the nitrogen…

• A. Peroxide
• B. Super oxide
• C. Both contain equal quantity
• D. None of the above

Explanation: Potassium form normal oxide ( in which oxygen has oxidation state -2) K2O2.

• A. Mg (OH)2
• B. AI(OH)3
• C. Si (OH)4
• D. None of the above

Explanation: The compound where hydrogen is attached to the highly electronegative element is considered to be most acidic.

• A. CCI4
• B. SiCl4
• C. CH4
• D. None of the above

Explanation: Silicon can be hydrolysed by water because the silicon atom of silicon tetrachloride has energetically suitable vacant d-orbitals.

• A. Boric acid
• B. Aluminum oxide
• C. Phosphorus pent oxide
• D. All of the above

Explanation: Amorphous solid, any noncrystalline solid in which the atoms and molecules are not organized in a definite lattice pattern.

• A. SiCl2
• B. SiCl4
• C. Si2CI3
• D. SiCl

Explanation: When chlorine gas is passed over powdered silicon and heated, it produces silicon tetrachloride (SiCl4), which is a colourless liquid.The…

• A. Li2CO3
• B. NaNO3
• C. Ba(NO3)2
• D. Na2CO3
• E. Non

Explanation: Na₂CO₃ is highly stable and resists decomposition even at high temperatures (above 1600°C).

• A. Sodium and mercury metals
• B. Sodium and lead
• C. Sodium and zinc
• D. None

Explanation: Sodium Mercury Amalgam is a alloy of sodium and mercury metals that functions as a strong reducing agent in chemical synthesis.

• A. Metal elements
• B. Reactive elements
• C. Unstable elements
• D. Rare earth elements

Explanation: Rare Earth elements are those which rarely combine with other elements to form compounds and are unreactive.