D & f- BLOCK ELEMENTS practice · Mixed difficulty

Gadolinium belongs of 4f series. Its atomic number is 64. Which of the following is the correct electric
Configuration of gadolinium?

Assertion: $d^5$ configuration is more stable than $d^4$

Reason: $d^5$ has more exchange energy as compared to $d^4$ because 10 & 6 exchanges are possible in $d^5$ & $d^4$ respectively.

A clock spring is heated to a high temperature and then suddenly plunged into cold water. This treatment will cause the metal to become:

From sodium agrentocyanide $\mathrm{Na}\left[ {\mathrm{Ag}{{\left( {\mathrm{CN}} \right)}_2}} \right]$, silver is precipitated by adding a powder of:

Which one of the following pairs of elements is called ‘chemical twins’ because of their very similar chemical properties?

Which of the following is not a characteristic of transition elements?

Assertion : Actinides show much higher range of oxidation states

Reason : Energy difference between 5f and 6d orbitals is large

Consider the following statements.

(I)$\mathrm{La}{\left( {\mathrm{OH}} \right)_3}$ is the least basic among hydroxides of lanthanides

(II) $\mathrm{Z}{\mathrm{r}^{4 + }}$ and $\mathrm{H}{\mathrm{f}^{4 + }}$ possess almost the same ionic radii

(III) $\mathrm{C}{\mathrm{e}^{4 + }}$ can act as an oxidizing agent

Which of the above is/are true?

Wrong match is

The colour of $\mathrm{CuC}{\mathrm{r}_2}{\mathrm{O}_7}$ solution in water is green because:

Which metal has the highest melting point?

An element which is highly toxic for plants and animals is:

which of the following does not exist

Which of the following statements are correct?

(i) Interstitial compounds contain non-metal atoms trapped inside the metal crystal whereas alloys are homogeneous blend of metals.

(ii) Steel and bronze are alloys of transition and nontransition metals.

(iii) Some boride containing interstitial compounds are very hard comparable to that of diamond.

(iv) Interstitial compounds are chemically more reactive than parent metal.

Useful lanthanoid member is:

The EAN of metal atoms in $M{n_2}{\left( {CO} \right)_{10}}$ and $C{o_2}{\left( {CO} \right)_8}$ respectively are:

The process of heating of steel to temperature much below redness and then slowly cooling is called:

Which of the following has more unpaired d-electrons?

The formula mass of Mohr’s salt is 392. The iron present in it is oxidised by $KMn{O_4}$ in acid medium. The equivalent mass of Mohr’s salt is

Silver halides are used in photography because they are:

The equilibrium $\mathrm{C}{\mathrm{r}_2}\mathrm{O}_7^{2 - } + 2e\leftrightharpoons2\mathrm{CrO}_4^{2 - }$:

In chromyl chloride, the number of d-electrons present on chromium is same as in (Given at. no. of $\text{Ti:} 22, \, \text{V:} 23, \, \text{Cr:}24, \, \text{Mn:} 25, \, \text{Fe:} 26$)

Which of the following is called white vitriol?

Number of electrons present in $4 {f}$ orbital of ${Ho}^{3+}$ ion is .......
(Given Atomic No. of ${Ho}=67$ )

${I}_2+{Na}_2 {CO}_3$ sol$^{\mathrm{n}} . \stackrel{\Delta}{\longrightarrow} {X}+{Y}$

If '${X}$' gives coloured ppt. with ${Pb}\left({CH}_3 {COO}\right)_2$ solution, then '${Y}$' will not be respond to which of the following

Consider the following statements

I. $Sc$ has a low value of $E_{{M^{ + 3}}/{M^{ + 2}}}^0$

II. $Zn$ has the highest value of $E_{{M^{ + 3}}/{M^{ + 2}}}^0$

III. $Mn$ and $Fe$ have comparatively high and low values of $E_{{M^{ + 3}}/{M^{ + 2}}}^0$ respectively

The correct set of statements is (Choose the low values of $E_{{M^{ + 3}}/{M^{ + 2}}}^0$ respectively).

The correct set of statements is (Choose the appropriate option)

Blue vitriol is:

The fraction of chlorine precipitated by $\mathrm{AgN}{\mathrm{O}_3}$ solution from $\left[ {\mathrm{Co}{{\left( {\mathrm{N}{\mathrm{H}_3}} \right)}_5}\mathrm{Cl}} \right]\mathrm{C}{\mathrm{l}_2}$ is:

Which of the following lanthanide is commonly used?

Which of the following has the maximum number of unpaired $d$-elelments?