D & F Block

Why are Zn, Cd, and Hg not considered transition elements?.

In the 3d series, which element has the lowest enthalpy of atomization and why?.

Why is the melting point of Manganese (Mn) anomalously low compared to its neighbors?.

Why do the atomic radii of the second (4d) and third (5d) transition series exhibit very similar values (e.g., Zr ≈ Hf)?.

Why is the first Ionisation Enthalpy (IE) of Zn higher than expected, while Cr is lower?.

Why is the second Ionisation Enthalpy of Cu unusually high?.

Identify the transition element in the 3d series that does not exhibit variable oxidation states.

In Group 6, why is Cr(VI) a strong oxidizing agent while Mo(VI) and W(VI) are stable?.

Why is the highest oxidation state of a transition metal usually exhibited in its oxides or fluorides?.

Which 3d metal fluoride exhibits the +7 oxidation state? (Trick Question).

Why is the $E^\circ (M^{2+}/M)$ value for Copper positive (+0.34 V)?.

Why are $E^\circ$ values for Mn, Ni, and Zn more negative than the trend suggests?.

Why is $Cr^{2+}$a reducing agent while$Mn^{3+}$is an oxidizing agent (both are$d^4$ )?.

Why is $Co^{3+}$a strong oxidizing agent in aqueous solution?.

Why is the $E^\circ (M^{3+}/M^{2+})$value for Scandium very low?.

Calculate the 'spin-only' magnetic moment for a divalent ion ( $Z=25$ ).

Why is $Ti^{4+}$colourless while$Ti^{3+}$is purple?.

Why does the magnetic moment of $Co^{2+}$ differ from the spin-only value?.

Why is $[Ni(CN)_4]^{2-}$diamagnetic while$[NiCl_4]^{2-}$is paramagnetic?.

Why do transition metals form many complexes?.

How do transition metals act as catalysts?.

What physical property do interstitial compounds (like $TiC$ ) retain from the metal?.

Why are interstitial compounds chemically inert and hard?.

Why are transition metal alloys readily formed?.

What is the starting material for $K_2Cr_2O_7$ prep?.

Why is $Na_2Cr_2O_7$ NOT used as a primary standard?.

What happens to pH and color if alkali is added to Dichromate?.

Write the ionic equation for $Fe^{2+}$oxidation by dichromate.

What is the Cr-O-Cr bond angle in $Cr_2O_7^{2-}$ ?.

Why is $KMnO_4$ coloured despite $Mn(VII)$having$d^0$ ?.

How is green manganate converted to permanganate in the lab?.

What happens when $KMnO_4$ is heated at 513 K?.

Why avoid HCl in permanganate titrations?.

Reaction of Permanganate with Thiosulphate (neutral/alkaline)?.

Reaction of Permanganate with Iodide (Acidic vs Neutral)?.

Why is separation of Lanthanoids difficult?.

Which Lanthanoid exhibits stable +4 state and why?.

Why is $Eu^{2+}$a strong reducing agent?.

Which trivalent Lanthanoid ions are diamagnetic?.

What is "Mischmetall" composed of?.

Product of Lanthanoids + Nitrogen?.

Why is Actinoid Contraction greater than Lanthanoid?.

Why do Actinoids show a wide range of oxidation states?.

Which Actinoids show max oxidation state +7?.

Why are IE of early Actinoids lower than Lanthanoids?.

Why is Actinoid chemistry complex?.

General electronic configuration of Actinoids?.

Name the last Actinoid and its stable OS.

Reaction of Actinoids with boiling water?.

Which actinoid formally has no 5f electrons in ground state?.

Why is $Cu^{2+}(aq)$more stable than$Cu^+(aq)$despite$Cu^+$having a stable$3d^{10}$configuration?

Why is the highest oxidation state of Mn +7 in oxides ( $Mn_2O_7$ ) but only +4 in fluorides ( $MnF_4$ )?

Why is HCl not used to acidify $KMnO_4$ solutions in titrations?

In Group 6, why is $Cr(VI)$a strong oxidant (e.g., Dichromate) while$Mo(VI)$and$W(VI)$ are stable?

Why is the separation of Zirconium (4d) and Hafnium (5d) extremely difficult?

What happens when $Cu^{2+}$is treated with Iodide ions ( $I^-$ )? (Write the observation).

$Cr^{3+}$and$Co^{2+}$both have 3 unpaired electrons. Why is the magnetic moment of$Co^{2+}$higher?

Why does Copper not replace Hydrogen from acids ( $E^\circ_{Cu^{2+}/Cu} = +0.34V$ )?

Explain the colour change when an acidic solution of Dichromate (Orange) is made alkaline.

Why do Actinoids form complexes more readily and use f-orbitals in bonding compared to Lanthanoids?

How does the chemical reactivity and conductivity of interstitial compounds compare to the parent metal?

What is the trend in the basic character of Lanthanoid hydroxides ( $La(OH)_3$ to $Lu(OH)_3$ ) and why?

In the reaction between Iodide and Persulphate catalysed by Fe(III), what role does Fe(II) play?

Which of these is colourless: $TiCl_3$ or $TiCl_4$ ? Why?

What happens when green Manganate ion ( $MnO_4^{2-}$ ) is placed in an acidic or neutral solution?