Zinc II Oxide

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. 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 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. 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. 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. Aluminium hydroxide is precipitated in Group ____.

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