All Free Chemistry MCQs with Answers

• A. Zero
• B. Two
• C. Four
• D. Six

Explanation: In [Co(NH3)6]+3, the coordination number of cobalt is six.

• A. Square planar
• B. Tetrahedral
• C. Octahedral
• D. Linear

Explanation: Cu(NH3)4]4+ has a square planar structure.

• A. K4CrO4
• B. K2Cr2O4
• C. Cr2O6
• D. CrCl3

Explanation: Chromium is in the +3 oxidation state. Each oxygen atom contributes -2, and there are two oxygen atoms per chromium atom, so in total, the…

• A. Oxidizing agent
• B. Reducing agent
• C. An Acid
• D. A base

Explanation: Potassium dichromate is commonly used as an oxidizing agent in acidic medium.

• A. Fe
• B. Ni
• C. Co
• D. All

Explanation: All of the elements mentioned (Fe, Ni, and Co) can form interstitial compounds under suitable conditions.

• A. Aluminium
• B. Copper
• C. Carbon
• D. Nickel

Explanation: Carbon is an essential element in steel production and is always present.

• A. Binding energy
• B. Covalent radius
• C. Melting point
• D. Cationic radius

Explanation: The cationic radius of transition elements does not vary with a regular pattern because the number of electrons in the outermost shell…

• A. 3
• B. 4
• C. 6
• D. 0

Explanation: The coordination number of cobalt in the complex is 6 because there are 6 ligands (3 NO2 and 3 NH3) attached to the cobalt atom.

• A. Zn, Cd, Hg
• B. Cu, Au, Ag
• C. Fe, Ru, Os
• D. Cr, Mo, w

Explanation: It is correct because these elements belong to Group IB of the transition elements.

• A. Number of electron pairs
• B. Number of unpaired electrons
• C. Number of Neutrons
• D. Number of protons

Explanation: Number of unpaired electrons is correct because the strength of binding energy in transition elements primarily depends on the presence of…

• A. Y
• B. Sc
• C. Zn
• D. Cd

Explanation: Sc (Scandium) is correct because the first transition series begins with scandium.

• A. Zn, Cd, Hg
• B. Cu, Au, Ag
• C. Fe, Ru, Os
• D. Cr, Mo, W

Explanation: Group IIB of transition elements contains Zn (Zinc), Cd (Cadmium), and Hg (Mercury).

• A. Tetrahedral
• B. Trigonal bipyramidal
• C. Octahedral
• D. Square planar

Explanation: trigonal bipyramidal, corresponds to dsp3 hybridization, where an atom has five electron groups around it, leading to a trigonal…

• A. 6
• B. 4
• C. 1
• D. 2

Explanation: The coordination number of iron in K3[Fe(CN)6] is indeed 6. In this compound, the iron ion (Fe2+) is surrounded by six cyanide ions (CN-)…

• A. Fe and Mn
• B. Fe3+ and Mn2+
• C. Fe2+ and Mn3+
• D. Fe2+ and Mn2+

Explanation: Fe3+ and Mn2+ have the highest number of unpaired electrons, which leads to stronger paramagnetic behavior compared to other options.

• A. Fe3O4
• B. Fe2O2
• C. FeO
• D. Fe(OH)2

Explanation: Magnetite is a naturally occurring iron oxide with the chemical formula Fe3O4. It is a major iron ore mineral and has magnetic properties.

• A. MnSiO
• B. MnSiO2
• C. MnSiO3
• D. Mn2SiO2

Explanation: This is the correct answer. Slag, typically formed during metal smelting or refining processes, often contains manganese silicates among…

• A. HCrO3
• B. H2CrO4
• C. HCr2O7
• D. H2CrO6

Explanation: This is chromic acid, which can be deprotonated to form chromate salts, making it the correct answer.

• A. White
• B. Red
• C. Blue
• D. Yellow

Explanation: Chromates are well-known for their characteristic yellow color, which is evident in many chromate salts.

• A. H2SO4
• B. K2SO4
• C. KMnO4
• D. H2S

Explanation: Stadeler's process is indeed used for the synthesis of potassium permanganate (KMnO4).