Zinc II Oxide

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. The reaction of zinc with dilute and concentrated nitric acid, respectively, produces:

1. $N{O}_2$ and $NO$
2. $NO$ and $N{O}_2$
3. $N{O}_2$ and $N_{2}O$
4. $N_{2}O$ and $N{O}_2$

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

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

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

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

Q. The reaction of zinc with dilute and concentrated nitric acid, respectively, produces:

1. $N{O}_2$ and $NO$
2. $NO$ and $N{O}_2$
3. $N{O}_2$ and $N_{2}O$
4. $N_{2}O$ and $N{O}_2$

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. 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

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. 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)