All Free Chemistry MCQs with Answers

• A. Sulphuric acid
• B. Plastics
• C. Ethanol
• D. Tetraethyl lead

Explanation: TiCI4 is used as a catalyst in the Ziegler-Natta process, which helps convert ethylene into polyethylene.

• A. sp3
• B. dsp2
• C. dsp3
• D. d2sp3

Explanation: In this case, option D (d2sp3hybridization) is the correct answer as it shows octahedral geometry.

• A. OH
• B. CN
• C. CO
• D. N2H4

Explanation: N2H4 is not a monodentate ligand, it is a bidentate ligand.

• A. dsp2 , square planar
• B. sp3 , tetrahedral
• C. sp3d, trigonal bipyramidal
• D. d2sp3, octahedral

Explanation: In Wilkinson's catalyst, [RhCI(PPh3)3], the central rhodium (Rh) atom is in a +1 oxidation state with a d electron configuration.

• A. [MnO4]-
• B. [Co(NH3)6]3+
• C. [Fe(CN)6]3-
• D. [Cr(H2O)6]3+

Explanation: To have no d-electrons, the central metal must have a d configuration. In the permanganate ion [MnO4]- the oxidation state of Manganese…

• A. [Co(NH3)4NO2Cl] [(NH3)Cl]
• B. [Co(NH3)5Cl] [Cl(NO2)]
• C. [Co(NH3)5(NO2)] Cl2
• D. [Co(NH3)5] [(NO2)Cl2]

Explanation: Precipitating two moles of AgCl indicates that there are two chloride ions in the outer ionization sphere.

• A. [Cr(NH3)5SO4]Cl
• B. [Co(NH3)4SO4]NO2
• C. [Cr(NH3)5Cl]SO4
• D. Both (A) and (C)

Explanation: A white precipitate with BaCl2 indicates the presence of free sulfate ions (SO42-) in the solution, which form insoluble BaSO4.

• A. Potassium Alumino oxalate
• B. Potassium trioxalatoaluminate(III)
• C. Potassium aluminium(III) oxalate
• D. Potassium trioxalato aluminate(VI)

Explanation: Following IUPAC nomenclature rules for coordination compounds: the cation (Potassium) is named first.

• A. Tetraammine dihydroxo-platinum (IV) sulphate
• B. Dihydroxo tetraammine-platinum (V) sulphate
• C. Tetra-ammine dihydroxo-platinum (II) sulphate
• D. Dihydroxo tetraammine-platinum (IV) sulphate

Explanation: As per the nomenclature of complex compounds, the correct name of given compound is "Tetraammine dihydroxo-platinum (IV) sulphate".

• A. All the elements except Scandium show +2 oxidation state
• B. They show variable oxidation because of the involvement of the unpaired d-electrons in addition to s-electrons
• C. Fe+3 ion is more stable than Fe+2 ion
• D. First four elements in the highest oxidation state use all of the s and d electrons for bonding

Explanation: Many transition metals (except Sc) can show the +2 oxidation state, but not all do consistently.

• A. 4
• B. 5
• C. 6
• D. 8

Explanation: The coordination number is the number of donor atoms directly bonded to the central metal ion. In this complex.

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

Explanation: According to VSEPR theory and experimental evidence, the geometry that minimizes repulsion for a centralatom bonded to five other groups…

• A. +2, +3, 0
• B. +3, 0, +3
• C. +2, +3, +4
• D. 0, +3, +4

Explanation: For [Fe(CN)6]4-: Fe +6[-1]=-4. so Fe=+2. For [Co(NH3)3 (NO₂)3]: Co + 3(0) +3(-1)=0 so Co =+3. For [Ni(CO)4] Ni+4(0)=0 so Ni =0.

• A. Pyramidal
• B. Square planar
• C. Octahedral
• D. Bipyramidal

Explanation: There are five carbonyl (CO) ligands attached with central atom (Fe), so coordination no is 5.

• A. [Cu(H₂O6)]+2
• B. [Pt(C₂O4)2]-2
• C. [CuCl]-2
• D. All have the same stability

Explanation: Complexes with polydentate ligands are more stable because they form chelate rings.

• A. Estimating the concentration of iron
• B. Measuring the concentration of CN-
• C. Measuring the solid state magnetic moment.
• D. Thermally decomposing the compound.

Explanation: The different electronic arrangements (Fe(II) vs Fe(III)) would result in a different number of unpaired d-electrons on the ron center.

• A. Yellow, Green
• B. Red, Yellow
• C. Blue, Green
• D. Red, Blue

Explanation: In [Ti(H₂O6)]+3, yellow light is absorbed while most of the red and blue lights are transmitted, therefore the solution of [Ti(H206)]+3…

• A. 1
• B. 5
• C. 4
• D. Unpredictable

Explanation: In hexafluoroferrate(III), the iron is in the +3 oxidation state, giving it a d5 electron configuration.

• A. I- < H2O < NH3 < CN-
• B. CN- < I- < H2O < NH3
• C. CN- < NH3 < H2O < I-
• D. NH3 < H2O < I- < CN-

Explanation: This question asks for the order of ligand strength according to the spectrochemical series arranges ligands based on their ability to…

• A. 4
• B. 2
• C. 6
• D. -4

Explanation: The coordination number refers to the number of atoms or ions bonded directly to the central atom in a complex ion or molecule.