Practical & Analytical Chemistry · JEE Main previous year questions

Bromine trifluoride autoionizes to form $\mathrm{Br}{\mathrm{F}}_2^{\oplus }$ and $\mathrm{Br}{\mathrm{F}}_4^{\ominus }$. The shapes of the cation and anion are respectively ____ , and ____ .

1. A.bent, square planar
2. B.linear, square planar
3. C.bent, see-saw
4. D.linear, tetrahedral

Treatment of a gas '$X$' with a freshly prepared ferrous sulphate solution gives a compound '$Y$' as a brown ring. The compounds $X$ and $Y$ are.

1. A.$\text{NO}$ and $[\text{Fe}(\text{NO})]{\text{SO}}_4$
2. B.${\text{NO}}_2$ and $[\text{Fe}({\text{NO}}_2)]{\text{SO}}_4$
3. C.${\text{N}}_2\text{O}$ and $[\text{Fe}({\text{N}}_2\text{O})]{\text{SO}}_4$
4. D.${\text{N}}_2{\text{O}}_4$ and $[\text{Fe}({\text{N}}_2{\text{O}}_4)]{\text{SO}}_4$

Among $\mathrm{F}{\mathrm{e}}^{3+}$, $\mathrm{P}{\mathrm{b}}^{2+}$, $\mathrm{C}{\mathrm{u}}^{2+}$ and $\mathrm{M}{\mathrm{n}}^{2+}$, identify the one that gets precipitated out while passing ${\mathrm{H}}_2\mathrm{S}$ in presence of $\mathrm{N}{\mathrm{H}}_4\mathrm{OH}$ as group reagent. The highest possible oxidation state of the corresponding metal is

1. A.+3
2. B.+4
3. C.+2
4. D.+7

A salt with few drops of conc. $\mathrm{HCl}$ gives apple green colour in flame test. The group precipitate of the salt is dissolved in acetic acid and treated with ${\mathrm{K}}_2\mathrm{Cr}{\mathrm{O}}_4$ to give yellow precipitate. When the sodium carbonate extract of the salt solution is heated with conc. $\mathrm{HN}{\mathrm{O}}_3$ and ammonium molybdate, it resulted a canary yellow precipitate. The cation and anion present in the salt are respectively,

1. A.$\mathrm{C}{\mathrm{a}}^{2+}$ and $\mathrm{S}{\mathrm{O}}_4^{2-}$
2. B.$\mathrm{B}{\mathrm{a}}^{2+}$ and $\mathrm{P}{\mathrm{O}}_4^{3-}$
3. C.$\mathrm{M}{\mathrm{n}}^{2+}$ and $\mathrm{P}{\mathrm{O}}_4^{3-}$
4. D.$\mathrm{B}{\mathrm{a}}^{2+}$ and $\mathrm{S}{\mathrm{O}}_4^{2-}$

1. A.C and E only
2. B.A and E only
3. C.A, B, D and E only
4. D.A, C and E only

Among the following cations, the number of cations which will give characteristic precipitate in their identification tests with ${\mathrm{K}}_4[\mathrm{Fe}(\mathrm{CN}{)}_6]$ is ____. $\mathrm{C}{\mathrm{u}}^{2+},\mathrm{F}{\mathrm{e}}^{3+},\mathrm{B}{\mathrm{a}}^{2+},\mathrm{C}{\mathrm{a}}^{2+},\mathrm{N}{\mathrm{H}}_4^{+},\mathrm{M}{\mathrm{g}}^{2+},\mathrm{Z}{\mathrm{n}}^{2+}$

Match List I with List II $$\begin{array}{llll}& \text{LIST I}& & \text{LIST II}\\ & \text{(Test)}& & \text{(Observation)}\\ \text{A.}& \mathrm{B}{\mathrm{r}}_2\text{ water test}& \text{I.}& \text{Yellow orange or orange red precipitate formed}\\ \text{B.}& \text{Ceric ammonium nitrate test}& \text{II.}& \text{Reddish orange colour disappears}\\ \text{C.}& \text{Ferric chloride test}& \text{III.}& \text{Red colour appears}\\ \text{D.}& \text{2, 4 - DNP test}& \text{IV.}& \text{Blue, Green, Violet or Red colour appears}\end{array}$$ Choose the correct answer from the options given below:

1. A.A-II, B-III, C-IV, D-I
2. B.A-III, B-IV, C-I, D-II
3. C.A-I, B-II, C-III, D-IV
4. D.A-IV, B-I, C-II, D-III

Consider the following test for a group-IV cation. ${\mathrm{M}}^{2+}+{\mathrm{H}}_2\mathrm{S}\to \mathrm{A}$ (Black precipitate)$+\mathrm{byproduct}$ $\mathrm{A}+\mathrm{aqua}\mathrm{regia}\to \mathrm{B}+\mathrm{NOCl}+\mathrm{S}+{\mathrm{H}}_2\mathrm{O}$ $\mathrm{B}+\mathrm{KN}{\mathrm{O}}_2+\mathrm{C}{\mathrm{H}}_3\mathrm{COOH}\to \mathrm{C}+\mathrm{byproduct}$ The spin-only magnetic moment value of the metal complex C is ____ BM (Nearest integer)

Match List I with List II LIST I (Name of the test) A. Borax bead test B. Charcoal cavity test C. Cobalt nitrate test D. Flame test LIST II (Reaction sequence involved) [M is metal] I. $\mathrm{MC}{\mathrm{O}}_3\to \mathrm{MO}\underset{+\mathrm{\Delta }}{\overset{\mathrm{Co}(\mathrm{N}{\mathrm{O}}_3{)}_2}{\to }}\mathrm{CoO}\cdot \mathrm{MO}$ II. $\mathrm{MC}{\mathrm{O}}_3\to \mathrm{MC}{\mathrm{l}}_2\to {\mathrm{M}}^{2+}$ III. $\mathrm{MS}{\mathrm{O}}_4\underset{\mathrm{\Delta }}{\overset{\mathrm{N}{\mathrm{a}}_2{\mathrm{B}}_4{\mathrm{O}}_7}{\to }}\mathrm{M}(\mathrm{B}{\mathrm{O}}_2{)}_2\to \mathrm{MB}{\mathrm{O}}_2\to \mathrm{M}$ IV. $\mathrm{MS}{\mathrm{O}}_4\underset{\mathrm{\Delta }}{\overset{\mathrm{N}{\mathrm{a}}_2\mathrm{C}{\mathrm{O}}_3}{\to }}\mathrm{MC}{\mathrm{O}}_3\to \mathrm{MO}\to \mathrm{M}$ Choose the correct answer from the options given below:

1. A.A-III, B-I, C-IV, D-II
2. B.A-III, B-IV, C-I, D-II
3. C.A-III, B-II, C-IV, D-I
4. D.A-III, B-I, C-II, D-IV

In qualitative test for identification of presence of phosphorus, the compound is heated with an oxidising agent. Which is further treated with nitric acid and ammonium molybdate respectively. The yellow coloured precipitate obtained is :

1. A.$\mathrm{N}{\mathrm{a}}_3\mathrm{P}{\mathrm{O}}_4\cdot 12Mo{\mathrm{O}}_3$
2. B.$(\mathrm{N}{\mathrm{H}}_4{)}_3\mathrm{P}{\mathrm{O}}_4\cdot 12(\mathrm{N}{\mathrm{H}}_4{)}_2\mathrm{Mo}{\mathrm{O}}_4$
3. C.$\mathrm{MoP}{\mathrm{O}}_4\cdot 21N{\mathrm{H}}_4\mathrm{N}{\mathrm{O}}_3$
4. D.$(\mathrm{N}{\mathrm{H}}_4{)}_3\mathrm{P}{\mathrm{O}}_4\cdot 12Mo{\mathrm{O}}_3$

Given below are two statements : Statement (I) : The gas liberated on warming a salt with dil ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4$, turns a piece of paper dipped in lead acetate into black, it is a confirmatory test for sulphide ion. Statement (II) : In statement-I the colour of paper turns black because of formation of lead sulphite. In the light of the above statements, choose the most appropriate answer from the options given below :

1. A.Both Statement I and Statement II are false
2. B.Statement I is true but Statement II is false
3. C.Both Statement I and Statement II are true
4. D.Statement I is false but Statement II is true

Sugar which does not give reddish brown precipitate with Fehling's reagent, is :

1. A.Glucose
2. B.Sucrose
3. C.Lactose
4. D.Maltose

In chromyl chloride test for confirmation of $\mathrm{C}{\mathrm{l}}^{-}$ ion, a yellow solution is obtained. Acidification of the solution and addition of amyl alcohol and $10\%{\mathrm{H}}_2{\mathrm{O}}_2$ turns organic layer blue indicating formation of chromium pentoxide. The oxidation state of chromium in that is

1. A.$+6$
2. B.$+5$
3. C.$+3$
4. D.$+10$

On passing a gas, 'X', through Nessler's reagent, a brown precipitate is obtained. The gas 'X' is

1. A.$\mathrm{C}{\mathrm{l}}_2$
2. B.$\mathrm{C}{\mathrm{O}}_2$
3. C.$\mathrm{N}{\mathrm{H}}_3$
4. D.${\mathrm{H}}_2\mathrm{S}$

A reagent which gives brilliant red precipitate with Nickel ions in basic medium is

1. A.dimethyl glyoxime
2. B.sodium nitroprusside
3. C.meta-dinitrobenzene
4. D.neutral $\mathrm{FeC}{\mathrm{l}}_3$

The oxidation number of iron in the compound formed during brown ring test for $\mathrm{N}{\mathrm{O}}_3^{-}$ ion is _________.

In the wet tests for detection of various cations by precipitation, ${\mathrm{Ba}}^{2+}$ cations are detected by obtaining precipitate of

1. A.${\mathrm{BaSO}}_4$
2. B.${\mathrm{Ba}(\mathrm{OAc})}_2$
3. C.${\mathrm{BaCO}}_3$
4. D.$\mathrm{Ba}(\mathrm{ox})$ : Barium oxalate

Match List - I with List - II: | List - I Species | List - II Geometry/Shape | | :--- | :--- | | A. ${\mathrm{H}}_3{\mathrm{O}}^{+}$ | I. Tetrahedral | | B. Acetylide anion | II. Linear | | C. $\mathrm{N}{\mathrm{H}}_4^{+}$ | III. Pyramidal | | D. $\mathrm{Cl}{\mathrm{O}}_2^{-}$ | IV. Bent | Choose the correct answer from the options given below:

1. A.A-III, B-I, C-II, D-IV
2. B.A-III, B-II, C-I, D-IV
3. C.A-III, B-IV, C-I, D-II
4. D.A-III, B-IV, C-II, D-I

When a solution of mixture having two inorganic salts was treated with freshly prepared ferrous sulphate in acidic medium, a dark brown ring was formed whereas on treatment with neutral $\mathrm{FeC}{\mathrm{l}}_3$, it gave deep red colour which disappeared on boiling and a brown red ppt was formed. The mixture contains :

1. A.$\mathrm{S}{\mathrm{O}}_3^{2-}\&{\mathrm{C}}_2{\mathrm{O}}_4^{2-}$
2. B.$\mathrm{C}{\mathrm{H}}_3\mathrm{CO}{\mathrm{O}}^{-}\&\mathrm{N}{\mathrm{O}}_3^{-}$
3. C.${\mathrm{C}}_2{\mathrm{O}}_4^{2-}\&\mathrm{N}{\mathrm{O}}_3^{-}$
4. D.$\mathrm{S}{\mathrm{O}}_3^{2-}\&\mathrm{C}{\mathrm{H}}_3\mathrm{CO}{\mathrm{O}}^{-}$

1. A.
2. B.
3. C.
4. D.

The number of following factors which affect the percent covalent character of the ionic bond is _________ (A) Polarising power of cation (B) Extent of distortion of anion (C) Polarisability of the anion (D) Polarising power of anion

Element not present in Nessler's reagent is :

1. A.$\mathrm{I}$
2. B.$\mathrm{N}$
3. C.$\mathrm{K}$
4. D.$\mathrm{Hg}$

Given below are two statements : Statement I: Upon heating a borax bead dipped in cupric sulphate in a luminous flame, the colour of the bead becomes green Statement II: The green colour observed is due to the formation of copper(I) metaborate In light of the above statements, choose the most appropriate answer from the options given below :

1. A.Both Statement I and Statement II are false
2. B.Both Statement I and Statement II are true
3. C.Statement I is false but Statement II is true
4. D.Statement I is true but Statement II is false

During the borax bead test with $\mathrm{CuS}{\mathrm{O}}_4$, a blue green colour of the bead was observed in oxidising flame due to the formation of :

1. A.CuO
2. B.$\mathrm{Cu}(\mathrm{B}{\mathrm{O}}_2{)}_2$
3. C.$\mathrm{C}{\mathrm{u}}_3{\mathrm{B}}_2$
4. D.Cu

"A" obtained by Ostwald's method involving air oxidation of $\mathrm{N}{\mathrm{H}}_3$, upon further air oxidation produces "B", "B" on hydration forms an oxoacid of Nitrogen along with evolution of "A". The oxoacid also produces "A" and gives positive brown ring test. Identify A and B, respectively :

1. A.${\mathrm{N}}_2{\mathrm{O}}_3,\mathrm{N}{\mathrm{O}}_2$
2. B.$\mathrm{N}{\mathrm{O}}_2,{\mathrm{N}}_2{\mathrm{O}}_5$
3. C.$\mathrm{N}{\mathrm{O}}_2,{\mathrm{N}}_2{\mathrm{O}}_4$
4. D.$\mathrm{NO},\mathrm{N}{\mathrm{O}}_2$