Zinc II Oxide

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. 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. Both acid and base may react with which of the following oxides?

1. $CaO$
2. $Cr{O}_3$
3. $ZnO$
4. $M{n}_2{O}_7$

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. Aluminium hydroxide is precipitated in Group ____.

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

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

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