Roasting

Q.

What will you observe when H₂S gas is passed through copper sulphate solution?

Q.

How is acetylene prepared in the laboratory?

Q. Analyze the reaction given below:
$\text{A}\stackrel{Calcination}{\to }\text{CaO(s)}+\text{MgO(s)}+{\text{2CO}}_2\text{(g)}$
Find out A.

1. ${\text{CaCO}}_3$
2. ${\text{MgCO}}_3$
3. ${\text{CaCO}}_3.{\text{MgCO}}_3$
4. ${\text{CaSO}}_4.{\text{MgCO}}_3$

Q. $A$ and $B$ are two ores of copper.
$A$ undergoes calcination to form a solid, $C{O}_{2\left(g\right)}$ and $O_{2\left(g\right)}$
$B$ undergoes roasting to form a solid and a gas $C$ which turns acidified $K_{2}C{r}_2{O}_7$ to green solution.
$B$ also reacts with dil $HCl$ to form a solid and gas $D$ which turns lead acetate solution black. $D$ also reacts with $C$ to form colloidal sulphur in the presence of moisture.

The gas ($C$) acts as a/an:

1. Oxidising agent
2. Reducing agent
3. Both (a) & (b)
4. Fluxing agent

Q. Choose the correct option using the code regarding roasting process.
I) It is the process of heating the ore in air in a reverberatory furnace to obtain the oxide.
II) It is an exothermic process.
III) It is used for the concentration of sulphide ore.
IV) It removes easily oxidisable volatile impurities present in the concentrated ore.

1. I, II and III
2. I, II and IV
3. I, III and IV
4. I, II, III and IV

Q. Match the column:
$\begin{array}{cccc}& & & \\ & \text{Column-I}& & \text{Column-II}\\ \left(a\right)& \text{Anglesite}& \text{(p)}& \text{Sulphate ore}\\ \left(b\right)& \text{Galena}& \text{(q)}& \text{Sulphide ore}\\ \left(c\right)& \text{Cerussite}& \text{(r)}& \text{Ore of Pb}\\ \left(d\right)& \text{Cinnabar}& \text{(s)}& \text{Carbonate ore}\\ & & \text{(t)}& \text{Ore of Hg}\end{array}$

1. (a) p, r; (b) q, r; (c) r, s (d) q, t
2. (a) q, r; (b) p, r; (c) r, s (d) q, t
3. (a) p, r; (b) q, r; (c) q, t (d) r, s
4. (a) q, t; (b) q, r; (c) r, s (d) p, r

Q. $A$ and $B$ are two ores of copper.
$A$ undergoes calcination to form a solid, $C{O}_{2\left(g\right)}$ and $O_{2\left(g\right)}$
$B$ undergoes roasting to form a solid and a gas $C$ which turns acidified $K_{2}C{r}_2{O}_7$ to green solution.
$B$ also reacts with dil $HCl$ to form a solid and gas $D$ which turns lead acetate solution black. $D$ also reacts with $C$ to form colloidal sulphur in the presence of moisture.

The gas ($C$) acts as a/an:

1. Oxidising agent
2. Reducing agent
3. Both (a) & (b)
4. Fluxing agent

Q. Match the conversion in $ColumnI$ with the type(s) of reaction(s) given in $ColumnII$.
$$\begin{array}{cccc}& ColumnI& & ColumnII\\ A.& PbS⟶PbO& p.& Roasting\\ B.& CaC{O}_3⟶CaO& q.& Calcination\\ C.& ZnS⟶Zn& r.& Carbonreduction\\ D.& C{u}_{2}S⟶Cu& s.& Self-reduction\end{array}$$

1. $A.\to p;B.\to q;C.\to p,r;D.\to p,s.$
2. $A.\to p,s;B.\to q;C.\to p,q,r;D.\to p,s.$
3. $A.\to s;B.\to q;C.\to p,r;D.\to p,s.$
4. $A.\to p,s;B.\to q,r;C.\to p,r;D.\to p,s.$