Copper II Oxide

Q. A metal nitrate $A$ on heating gives yellowish brown coloured metal oxide along with brown gas $B$ and a colourless gas $C$. An aqueous solution of $A$ on reaction with potassium iodide forms a yellow precipitate of compound $D$. Identify $A,B,C$ and $D$. Also, identify the types of reactions taking place. Metal present in $A$ is used in an alloy which is used for soldering purposes.

Q. Among the nitrate of alkali metals which one can be decomposed to its oxide :

1. ${NaNO}_3$
2. ${LiNO}_3$
3. All of these
4. ${KNO}_3$

Q. When an organic compound is heated with dry cupric oxide and the gases evolved are passed through lime water which turns milky, the gas may be ______ or ______ .

Q. The main oxides formed on the combustion of $Li,Na$ and $K$ in excess of air are, respectively:

1. $Li{O}_2,N{a}_2{O}_2$ and $K_{2}O$
2. $L{i}_2{O}_2,N{a}_2{O}_2$ and $K{O}_2$
3. $L{i}_{2}O,N{a}_2{O}_2$ and $K{O}_2$
4. $L{i}_{2}O,N{a}_{2}O$ and $K{O}_2$

Q. Cupric oxide when heated to 1100-1200 degree Celsius gives $CuO\to A+O_2$

1. $C{u}_{2}O$
2. No Reaction possible
3. $Cu$
4. $C{u}_2{O}_3$

Q. RCOOH decomposes $NaHC{O}_3$ to liberate $C{O}_2$ which comes from______:

1. $NaHC{O}_2$
2. $NaHCO$
3. $NaOHC{O}_3$
4. $NaHC{O}_3$

Q. Cupric oxide when heated to 1100-1200 degree Celsius gives $CuO\to A+O_2$

1. $Cu$
2. $C{u}_{2}O$
3. No Reaction possible
4. $C{u}_2{O}_3$

Q. Which of the following metal carbonates decomposes on heating?

1. ${MgCO}_3$
2. ${Na}_2{CO}_3$
3. ${Rb}_2{CO}_3$
4. $K_2{CO}_3$

Q. Cupric oxide when heated to 1100-1200 degree Celsius gives $CuO\to A+O_2$

1. $C{u}_{2}O$
2. No Reaction possible
3. $Cu$
4. $C{u}_2{O}_3$

Q. The solid residue $\left(B\right)$ is:

1. $CaO$
2. $ZnO$
3. $PbO$
4. $BaO$