All Free Chemistry MCQs with Answers

• A. Haematite
• B. Limonite
• C. Siderite
• D. Magnetite

Explanation: Haematite is considered a good-quality iron ore because it contains a high percentage of iron and low impurities, including low…

• A. The addition of an electron increases the volume of the electron cloud
• B. It increases the effective nuclear charge
• C. The repulsion between electrons increases with the addition of electrons
• D. The attraction between electrons and the nucleus increases

Explanation: The correct answer is that the repulsion between electrons increases with the addition of electrons.

• A. As
• B. Bi
• C. C
• D. Sb

Explanation: Metallic character refers to an element's ability to lose electrons. It increases as you move down a group in the periodic table because…

• A. AlF3 > AlBr3 > AlCl3 >> AlF3
• B. AlCl3 > AlF3 > AlBr3 > AlI3
• C. AlCl3 > AlBr3 > AlI2 > AlF3
• D. AlF3 > AlCl3 > AlBr3 > AlI3

Explanation: The order of ionic character is determined by the size of the halide ions.

• A. BiH3
• B. NH3
• C. HF
• D. SbH3

Explanation: The most stable hydride will have the greatest electronegativity difference since the bond energy will then also be the greatest.

• A. S electron
• B. p - electron
• C. d- electron
• D. f - electron

Explanation: Electronegativity is the tendency of an atom to attract electrons. In group 1 elements, as we go down the group, the atomic size increases…

• A. Colemanite
• B. Borax
• C. Diaspore
• D. bauxite

Explanation: The given formula, Na2B4O7.10H2O is that of borax.

• A. metallic
• B. Non-metallic
• C. metalloids
• D. transition elements

Explanation: These two are Metalloids because they do not conduct electricity but are metals.

• A. Barium Xenate
• B. Barium Xenthate
• C. Barium Prexenate
• D. Barium Perxenthate

Explanation: The correct name for Ba2XeO is Barium Perxenthate. The prefix 'per-' indicates a high oxidation state of xenon, which is consistent with…

• A. energy of dissociation
• B. electron affinity of atoms
• C. hydration energies of lons
• D. all of the above

Explanation: The halogens D are good oxidizers The oxidizing power of halogens in an aqueous medium depends on their electron affinity, bond…

• A. Helium
• B. Neon
• C. argon
• D. Xenon

Explanation: All of the noble gases are completely inert except for xenon. Under normal conditions, xenon is non-reactive, but at extreme temperatures…

• A. hydrogen gas
• B. salt and water
• C. a base
• D. An acid

Explanation: Non-metals are the elements that form negative ions by accepting or gaining electrons.

• A. bromine
• B. chlorine
• C. fluorine
• D. iodine 200

Explanation: For all elements in general, the higher the atomic number, the smaller the 1s orbital. The 1s orbital is closest to the nucleus.

• A. NaAlO3
• B. Na3Al2O6
• C. NaAlO2
• D. NaAl2O3

Explanation: The reaction between sodium hydroxide (NaOH) and aluminum oxide (Al2O3) results in the formation of sodium aluminate (NaAlO2) and water.

• A. 1s2 2s2 2p3
• B. 1s2 2s2 2p4
• C. 1s2 2s2 2p6 3s1
• D. 1s2 2s2 2p6 3s2 3p3

Explanation: Ionization energy is the energy required to remove an electron from an isolated gaseous atom.

• A. Increases
• B. Decreases
• C. Remains unchanged
• D. First increases and then decreases

Explanation: Down the group, from fluorine to iodine the reactivity increases as the bond energy decreases, making it easier for the phosphorus…

• A. HCIO
• B. HCIO2
• C. HCIO3
• D. HCIO4

Explanation: a) HCIO (Hypochlorous acid):This is the correct option. Hypochlorous acid (HCIO) is a weak acid with the chemical formula HClO.

• A. K2O
• B. MgO
• C. ZnO
• D. CaO

Explanation: Zinc oxide (ZnO) is the correct answer because it is an amphoteric oxide.

• A. H2S2O3
• B. H2S2O5
• C. H2S2O6
• D. H2S2O7

Explanation: The correct answer is H2S2O7, which represents oleum. Oleum is formed when sulfur trioxide (SO3) is dissolved in sulfuric acid (H2SO4)…

• A. Fe
• B. Co
• C. Ni
• D. Cu

Explanation: Atomic radius decreases across a period since all these elements belong to the same period of the d-block, copper is the last element in…