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11.
Prussian blue is formed when
A
ferrous sulphate reacts with $$FeC{l_3}$$
B
ferric sulphate reacts with $${K_4}Fe{\left( {CN} \right)_6}$$
C
ferrous ammonium sulphate reacts with $$FeC{l_3}$$
D
ammonium sulphate reacts with $$N{O_2}$$
Answer :
ferric sulphate reacts with $${K_4}Fe{\left( {CN} \right)_6}$$
13.
In the separation of $$C{u^{2 + }}$$ and $$C{d^{2 + }}$$ in 2nd group qualitative analysis of cations, tetrammine copper (II) sulphate and tetrammine cadmium (II) sulphate react with $$KCN$$ to form the corresponding cyano complexes. Which one of the following pairs of the complexes and their relative stability enable the separation of $$C{u^{2 + }}$$ and $$C{d^{2 + }}?$$
A
$${K_3}\left[ {Cu{{\left( {CN} \right)}_4}} \right]$$ more stable and $${K_2}\left[ {Cd{{\left( {CN} \right)}_4}} \right]$$ less stable
B
$${K_2}\left[ {Cu{{\left( {CN} \right)}_4}} \right]$$ less stable and $${K_2}\left[ {Cd{{\left( {CN} \right)}_4}} \right]$$ more stable
C
$${K_2}\left[ {Cu{{\left( {CN} \right)}_4}} \right]$$ more stable and $${K_2}\left[ {Cd{{\left( {CN} \right)}_4}} \right]$$ less stable
D
$${K_3}\left[ {Cu{{\left( {CN} \right)}_4}} \right]$$ less stable and $${K_2}\left[ {Cd{{\left( {CN} \right)}_4}} \right]$$ more stable
Answer :
$${K_3}\left[ {Cu{{\left( {CN} \right)}_4}} \right]$$ more stable and $${K_2}\left[ {Cd{{\left( {CN} \right)}_4}} \right]$$ less stable
$${K_3}\left[ {Cu{{\left( {CN} \right)}_4}} \right]$$ is more stable whereas $${K_2}\left[ {Cd{{\left( {CN} \right)}_4}} \right]$$ is less stable.
14.
Three separate samples of a solution of a single salt gave these results. One formed a white precipitate with excess ammonia solution, one formed a white precipitate with $$dil.\,NaCl$$ solution and one formed a black precipitate with $${H_2}S.$$ The salt could be
16.
Upon treatment with ammoniacal $${H_2}S,$$ the metal ion that precipitates as a sulfide is
A
$$Fe\left( {III} \right)$$
B
$$Al\left( {III} \right)$$
C
$$Mg\left( {II} \right)$$
D
$$Zn\left( {II} \right)$$
Answer :
$$Zn\left( {II} \right)$$
The group reagent of fourth group is ammoniacal $${H_2}S$$ by which $$Z{n^{2 + }}$$ ion will be precipitated as $$ZnS,$$ whereas $$F{e^{3 + }}\,{\text{ion}}$$ and $$A{l^{3 + }}\,{\text{ions}}$$ will be precipitated as hydroxides.
17.
A gas $$'X'$$ is passed through water to form a saturated solution. The aqueous solution on treatment with silver nitrate gives a white precipitate. The saturated aqueous solution also dissolves magnesium ribbon with evolution of a colourless gas $$'Y'$$. Identify $$'X'\,{\text{and}}\,'Y'$$.
A
$$X = C{O_2},Y = C{l_2}$$
B
$$X = C{l_2},Y = C{O_2}$$
C
$$X = C{l_2},Y = {H_2}$$
D
$$X = {H_2},Y = C{l_2}$$
Answer :
$$X = C{l_2},Y = {H_2}$$
Since the saturated aqueous solution of $$\left( X \right)$$ give white ppt with $$AgN{O_3},$$ so$$\left( X \right)$$ may be $$C{l_2}.$$ Hence
$$\mathop {C{l_2}}\limits_{\left( X \right)} + {H_2}O \to HOCl + HCl$$
$$HCl + AgN{O_3} \to \mathop {AgCl}\limits_{White} \downarrow + HN{O_3}$$
$$2HCl + Mg \to MgC{l_2} + \mathop {{H_2}}\limits_{\left( Y \right)} \uparrow $$
18.
For detection of sulphur in an organic compound sodium nitroprusside is added to the sodium extract. A violet colour is obtained due to formation of
A
$$Fe{\left( {CN} \right)_2}$$
B
$${K_3}Fe{\left( {CN} \right)_5}NS$$
C
$$N{a_4}\left[ {Fe{{\left( {CN} \right)}_5}NOS} \right]$$
19.
An orange precipitate of $$II$$ group is dissolved in $$conc.\,HCl;$$ the solution when treated with excess of water turns milky due to formation of
20.
A white sodium salt dissolves readily in water to give a solution which is neutral to litmus. When silver nitrate solution is added to the solution, a white precipitate is obtained which does not dissolve in $$dil.\,HN{O_3}.$$ The anion could be
A
$$CO_3^{2 - }$$
B
$$C{l^ - }$$
C
$$SO_4^{2 - }$$
D
$${S^{2 - }}$$
Answer :
$$C{l^ - }$$
$$NaCl$$ is a salt of strong acid and strong base hence on dissolution will give neutral solution.
$$NaCl + AgN{O_3} \to AgCl \downarrow + HN{O_3}$$