All Free Chemistry MCQs with Answers

• A. Fe+2 and Mn+2
• B. Fe+2 and Mn+3
• C. Fe+3 and Mn+3
• D. Fe+3 and Mn+2

Explanation: Here's a breakdown of the electron configurations for each ion:Fe+3: [Ar] 3d5Mn+2: [Ar] 3d5As you can see, both ions have 5 unpaired…

• A. Copper and Iron
• B. Copper and Mg
• C. Copper and Zinc
• D. Copper and Silver

Explanation: Brass is a binary alloy composed of copper (Cu) and zinc (Zn). The proportion of copper and zinc can vary, but it is typically a…

• A. Ammine
• B. Hydrazine
• C. Aqua
• D. Carbonyl

Explanation: Hydrazine - Correct. Hydrazine (N₂H₄) has two nitrogen atoms, each capable of donating a lone pair, making it a bidentate ligand.

• A. Atomic size
• B. Orbital configuration
• C. Very light
• D. Hard elements

Explanation: Transition metals have similar atomic sizes, allowing atoms of different metals to mix and form alloys.

• A. K2MnO4
• B. K2Cr2O7
• C. KMnO4
• D. Kl
• E. K2CrO4

Explanation: Heating a mixture of chromite (FeCr2O4) and K2CO3 (not KCO3 as mentioned in the question) in air is done to manufacture option (e)…

• A. Cu and Zn
• B. Cr and Fe
• C. Cr and Cu
• D. Mn and Co

Explanation: The correct answer is Cr and Cu. Chromium (Cr) has an electron configuration of [Ar] 3d5 4s1, which results in five unpaired electrons in…

• A. Cu+2
• B. Ni+2
• C. Fe+2
• D. Mn+2

Explanation: Charge on the central metal ion: In general, the greater the charge density on the central ion, the greater the stability of its…

• A. Cu+Zn+Ni
• B. Cu+Ag+Ni
• C. Cu+Sn+Zn+Pb
• D. Al+Cu+Mg+Mn

Explanation: German silver basically doesn't contain silver in it, so it might be a bit confusing its comp is 60% copper, 20% zinc, and 20% nickelThe…

• A. Ferric hexa cyano ferrate (i)
• B. Iron (III) hesa cyano ferrate (II)
• C. Sodium hexa cyano ferrate (III)
• D. Both (A) & (B)

Explanation: Opt A Prussian blue.Opt B Dark red to Dark purple to Dark blue powder to crystaline.Opt C Sodium ferrocyanide is an odorless yellow solid.

• A. (n-1) d1-10 na2
• B. (n-1)d1-10(n-1)s0-2
• C. (n-1)d1-10ns0-2
• D. nd1-10ns0-2

Explanation: The formula for calculating the required electronic configuration is (n-1)d1-10, ns1-2. Hence, only option C is correct.

• A. Number of ligands
• B. Hybridization of central metal
• C. Oxidation state of central metal
• D. Number of chelating agents

Explanation: The number of ligands affects the coordination number and overall stability of the complex.

• A. Bidentate
• B. lon
• C. Monodentate
• D. Crab claws
• E. Metal

Explanation: Chelates are sometimes metaphorically referred to as "crab claws" because of how they "grasp" a metal ion with multiple coordination…

• A. Br
• B. CN-
• C. C204-
• D. OH-
• E. CI

Explanation: Oxalate ion (C₂O₄²⁻): Bidentate ligand, anionic, coordinates through both oxygen atoms, forming chelate complexes with metal ions.

• A. steel
• B. brass
• C. bronze
• D. graphite

Explanation: Graphite is not an alloy. It is pure carbon. It is an allotrope.

• A. High melting points
• B. Good conductors of electricity
• C. Hard metals
• D. Ions and compounds are colorless

Explanation: Transition elements form colored complexes due to d-d transitions except Zn²⁺, Sc³⁺, and Cu⁺.

• A. 20-30
• B. 21-30
• C. 22-30
• D. 24-30

Explanation: The atomic number range for the 3d series, which includes the transition metals in the 3d subshell, is from 21 to 30.

• A. Amphoteric
• B. Neutral
• C. Oxidizing agent
• D. Reducing agent

Explanation: Vanadium can act as a reducing agent in various chemical reactions. A reducing agent is a substance that donates electrons to another…

• A. Normal Salt
• B. Mixed Salt
• C. Double Salt
• D. Complex Salt

Explanation: Potassium ferrocyanide, with the chemical formula K4Fe(CN)6, is considered a double salt.

• A. d to d orbital
• B. p to d orbital
• C. p to p orbital
• D. s to p orbital

Explanation: Transition metals show colored complexes due to their d-d transitions.

• A. Tin
• B. Zinc
• C. Aluminum
• D. Copper

Explanation: Zinc is used to galvanize iron sheets because it provides cathodic protection.