Zinc II Oxide

Q. Which gas will release when phenol react with sodium metal ?

1. Hydrogen
2. Oxygen
3. Carbon dioxide
4. Reaction does not take place

Q.

When metal X is treated with sodium hydroxide, a white precipitate (A) is obtained, which is soluble in excess of NaOH to give soluble complex (B). Compound (A) is soluble in dilute HCl to form compound (C). The compound (A) when heated strongly gives (D), which is used to extract metal. Identify (X), (A), (B), (C) and (D). Write suitable equations to support their identities.

Q. The only cations present in a slightly acidic solutions are $F{e}^{3+},Z{n}^{2+}\text{and}C{u}^{2+}$. The reagent that when added in excess to this solution would identify to separate $F{e}^{3+}$ in one step is

1. $3MHCl$
2. $6MN{H}_3$
3. $6MNaOH$
4. $H_{2}S$ gas

Q. The addition of $NaOH$ to $Z{n}^{2+}$ ion gives a white precipitate which on the addition of excess $NaOH$ dissolves the precipitate. In this solution, $Zn$ exists in:

1. $Z{n}^{2+}$ form
2. Cationic form
3. Anionic form
4. Both (b) & (c)

Q. The group reagent for group V radicals is

1. $(N{H}_4{)}_{2}C{O}_3$
2. $(N{H}_4{)}_{2}S{O}_4$
3. $N{H}_{4}Cl$
4. $(N{H}_4{)}_2{C}_2{O}_4$

Q. The cation that will not be precipitated by $H_{2}S$ in the presence of dil. $HCl$ is :

1. $C{u}^{2+}$
2. $A{s}^{3+}$
3. $C{o}^{2+}$
4. $P{b}^{2+}$

Q. When the same amount of zinc is treated separately with excess of sulphuric acid and excess of sodium hydroxide, the ratio of volumes of hydrogen evolved is $X:Y$. Find the value of $\frac{X}{Y}$.

Q. A green pigment is obtained when zinc oxide is heated with cobalt nitrate. This pigment is called the Rinmann’s green. Rinmann’s green is given by?

1. $CoZn{O}_2$
2. $CoZn{O}_3$
3. $CoO.Zn{O}_2$
4. CoO.ZnO

Q. Zinc on reaction with concentrated nitric acid produces ____ gas.

1. $NO$
2. $N{O}_2$
3. $H_2$
4. Both A and B

Q. A solution contains a group IV cation. It's sulphide precipitate dissolves in $dil.HCl$ on boiling. On addition of $NaOH$ to the dissolved sulphide precipitate solution in excess, a white precipitate is formed which turns brown due to atmospheric oxidation.
The cation is:

1. $Z{n}^{2+}$
2. $M{n}^{2+}$
3. $N{i}^{2+}$
4. $C{o}^{2+}$

Q. On passing $H_{2}S$ gas to the original solution from group III cation analysis gives a black precipitate. This indicate the presence of

1. $N{i}^{2+}$
2. $Z{n}^{2+}$
3. $M{n}^{2+}$
4. All of the above

Q. Find the number of amphoteric hydroxide(s) from the following:
$Be(OH{)}_2,Mg(OH{)}_2,Al(OH{)}_3,LiOH,B(OH{)}_3,$

Q. On treatment with cold water, an element (A) reacts readily liberating a colorless, odourless gas (B) and a solution (C). Lithium is reacted with (B) yielding a solid product (D) which effervescence with water to give a strongly basic solution (E). When $C{O}_2$ gas is bubbled through the solution (C), a white ppt (F) is formed but this redissolved forming solution (G) when more $C{O}_2$ is passed. The precipitate (F) effervesced when moistened with conc.$HCl$ and give deep red coloration to the Bunsen burner flame. (F) on heating with an excess of carbon at ${2000}^{o}C$ give (H).
Solid (H) on hydrolysis gives a gas, which on passing through ammonical $AgN{O}_3$ solution, yields:

1. no ppt
2. white ppt
3. red ppt
4. brown ppt

Q. Color of magnesium oxide is:

1. white
2. blue
3. grey
4. pink

Q.

Match the important chemicals given in Column (A) with the chemical formulae given in Column(B)

Column 1	Column 2
Plaster of Paris	Ca(OH)2
Gypsum	${\mathrm{CaSO}}_4.\frac{1}{2}{\mathrm{H}}_2\mathrm{O}$
Bleaching Powder	CaSO4.2H2O
Slaked Lime	CaOCI2

Q. An aqueous solution contains the following ions $H{g}_2^{2+},H{g}^{2+},p{b}^{2+}\text{and}C{u}^{2+}.$ The addition of $dil.HCl$ will precipitate out

1. $H{g}_{2}C{l}_2\text{and}HgC{l}_2$
2. $H{g}_{2}C{l}_2\text{and}PbC{l}_2$
3. $PbC{l}_2$ only
4. $PbC{l}_2\text{and}HgC{l}_2$

Q. In the following reactions, $ZnO$ is respectively acting as a/an:
(a) $ZnO+N{a}_{2}O\to N{a}_{2}Zn{O}_2$
(b) $ZnO+C{O}_2\to ZnC{O}_3$

1. Base and base
2. Acid and acid
3. Acid and base
4. Base and acid

Q. Out of the following metals which will give $H_2$ on reaction with $NaOH$
$I$ : $Zn$
$II$: $Al$
$III$ : $Be$

1. $I,II,III$
2. $I,III$ only
3. $II$ Only
4. $I$ only

Q. If $NaOH$ is added to an aqueous solution of zinc ions, a white precipitate appears and on adding excess $NaOH$, the precipitate dissolves. In this solution, zinc exists in the:

1. Cationic part
2. Anionic part
3. Both in the cationic and anionic parts
4. Precipitate

Q. Aluminium hydroxide is precipitated in Group ____.

1. II (B)
2. III
3. II (A)
4. IV

Q. The precipitate $P$ contains

1. $H{g}_{2^{2+}}$
2. $H{g}^{2+}$
3. $A{g}^{+}$
4. $P{b}^{2+}$

Q. Mark the correct statement/s about $ZnO$:

1. It is used as a catalyst along with $C{r}_2{O}_3$ in the manufacturing of methyl alcohol from water gas
2. It is amphoteric in nature
3. When heated with cobaltous nitrate, it forms a green colored compound - zinc cobaltonitrate also known as Rinmanns green
4. It is yellow when cold and white when hot

Q. An element forms an oxide $A_2{O}_3$ which is acidic in nature. $A$ will be :

1. non-metal
2. metal
3. noble gas
4. metalloid

Q. When sulphuric acid is added to a substance, a gas is released which is colourless, odourless and burns with a 'pop' sound. Guess the substance

1. Carbonates
2. Sulphates
3. Metals
4. None of the above

Q. Which of the following gives white precipitate when $HCl$ is added to its aqueous solution?

1. $H{g}^{+}$
2. $Z{n}^{2+}$
3. $M{g}^{2+}$
4. $C{d}^{2+}$

Q. A colourless aqueous solution contain nitrates of two metal, when it is added to an aqueous solution of $NaCl$, a white precipitate ws formed. This precipitate was found to be partially soluble in hot water to give a residue $P$ and a solution $Q$. The residue $P$ was solublein aq. in $N{H}_3$ and also in excess sodium thiosulfate. The hot solution $Q$ gave a yellow precipitate with $KI$. The metals $X$ and $Y$, respectively, are:

1. $Ag\text{and}Cd$
2. $Ag\text{and}Pb$
3. $Cd\text{and}Pb$
4. $Cd\text{and}Zn$

Q. How much amount of zinc is required to react with dilute $H_{2}S{O}_4$ for obtaining $224$ mL hydrogen at STP?

1. $0.65$ g
2. $6.5$ g
3. $65$ g
4. $0.065$ g

Q. When zinc oxide is heated with cobalt nitrate, a green mass is formed due to the formation of a compound which is known as Rinmann’s green. The compound is:

1. $Zn\left[Co{O}_2\right]$
2. $Co\left[Zn{O}_2\right]$
3. $Zn\left[Co\right(N{H}_3{)}_4]$
4. $Co\left[Zn\right(N{H}_3{)}_4]$

Q. Which of following does not give white precipitate of $AgCl$ on heating with silver nitrate.

1. $C{H}_{3}C{H}_{2}Cl$
2. $(C{H}_3{)}_{3}CCl$
3. $(C{H}_3{)}_{2}C{H}_{2}Cl$
4. $CC{l}_4$

Q. Assertion :$Sb\left(III\right)$ is not precipitated as sulphide when in its alkaline solution $H_{2}S$ is passed. Reason: Concentration of $S^{2-}$ ions in alkaline medium is inadequate for precipitation.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect