D & f- BLOCK ELEMENTS practice · Mixed difficulty

Metallic bonds do not play a role in:

The catalyst used for the hydrogenation of vegetable oils for making margarine is:

$\mathrm{CuS}{\mathrm{O}_4}aq$. Absorbs

Chromium has most stable oxidation state of:

A solution when diluted with ${\mathrm{H}_2}\mathrm{O}$ and boiled gives a white ppt. On addition of excess $\mathrm{N}{\mathrm{H}_4}\mathrm{Cl}/\mathrm{N}{\mathrm{H}_4}\mathrm{OH}$, the volume of precipitate decreases due to dissolution leaving behind a white gelatinous precipitate. The precipitate which dissolves in $\mathrm{N}{\mathrm{H}_4}\mathrm{OH}/\mathrm{N}{\mathrm{H}_4}\mathrm{Cl}$ is:

Which of the following compounds is used as the starting material for the preparation of potassium dichromate?

In which of the following pairs are both the ions coloured in aqueous solution

Which series of elements have nearly the same atomic radii?

The reduction potential of hydrogen electrode when placed in a buffer solution is found to be –0.591 V. The pH of the buffer is:

Which metal is not used for making coins?

The actinoids showing +7 oxidation state are

${\mathrm{K}_2}\mathrm{C}{\mathrm{r}_2}{\mathrm{O}_7}\mathop \to \limits^\Delta {\mathrm{K}_2}\mathrm{Cr}{\mathrm{O}_4} + {\mathrm{O}_2} + X\mathrm{\;}$
In the above reaction $X\;$ is

Zr (z=40) and Hf (z=72) have similar atomic radii because of

A blue colouration is not obtained when:

Copper sulphate is commercially made from copper scrap by:

Powdered silver ore is treated with NaCN solution and air is bubbled through the mixture to give:

The formula of mercurous ion is:

Which one of the following does not correctly represent the correct order of the property indicated against it?

Which of the following reagents does not convert copper sulphate to cuprous state?

Mercury forms amalgams with all except:

An element is in ${M^{3 + }}$ form. Its electronic configuration is $\left[ {\mathrm{Ar}} \right]3{d^1}$, the ion is

The incorrect statement(s) among (1)-(3) is (are)
1) W(VI) is more stable than Cr(VI).
2) In the presence of HCl, permanganate titrations provide satisfactory results.
3) Some lanthanoid oxides can be used as phosphors.

The one which has lowest ox. no. of Hg:

Which ion is blue in colour in aqueous medium?

In the equation,

$4 \mathrm{M}+8 \mathrm{CN}^{-}+2 \mathrm{H}_2 \mathrm{O}+\mathrm{O}_2 \rightarrow 4\left[\mathrm{M}(\mathrm{CN})_2\right]^{-}+4 \mathrm{OH}^{-}$

Identify the metal (M)

In order to oxidise a mixture of one mole of each of $Fe{C_2}{O_4},\,\,F{e_2}{({C_2}{O_4})_3},\,\,FeS{O_4}$ and $F{e_2}{(S{O_4})_3}$ in acidic medium, the number of moles of $KMn{O_4}$ required is

Silver nitrate produces a black stain on skin due to:

Which among the following is smallest in size?

Which of the following elements has the maximum first ionization potential?

Lanthanide contraction is due to increase in