Calcium and Its Compounds

Q.

$\mathrm{CaO}+{\mathrm{H}}_2\mathrm{O}\to \mathrm{Ca}{\left(\mathrm{OH}\right)}_2$ is an example of which reaction?

Q.

What is the chemical formula of the Borax Bead?

Q. Hybridization of [mn(cn)6]3-

Q.

Which of the following is present as an active ingredient in bleaching powder for bleaching action?

1. $Ca(OCl{)}_2$

2. $Ca{O}_{2}Cl$

3. $CaC{l}_2$

4. $CaOC{l}_2$

Q.

Calcium oxide reacts vigorously with water to produce slaked lime CaO(s)+H2O(l)→Ca(OH)2(aq) this reaction can be classified as:

Q.

The products obtained on heating${\mathrm{LiNO}}_3$ will be ___________, ________ and __________.

Q.

What is the product obtained when acetylene is treated with $\mathrm{HBr}$?

Q.

Explain in detail what happens when water is poured over Quicklime $\left(\mathrm{CaO}\right)$. Discuss all the physical observations and write the balanced chemical reaction involved.

Q. The percent of available chlorine in commercial sample of bleaching powder is usually $33-38\%$. This is due to

1. Impurities present in the original slaked lime and chlorine during its formation
2. Decomposition of bleaching powder when kept in air
3. Incomplete reaction between slaked lime and $C{l}_2$ during its formation
4. All of these

Q.

Explain with the equation, what is noticed when permanent hard water is treated
with (a) slaked lime and (b) washing soda.

Q. The suspension of slaked lime in water is known as:

1. aqueous solution of slaked lime
2. milk of lime
3. limewater
4. quicklime

Q. Which of the following oxide is expected to react readily with $NaOH$?

1. $N{a}_{2}O$
2. $CaO$
3. $NO$
4. $C{l}_2{O}_7$

Q. Which of the following reactions occur in blast furnance during the extraction of iron?

1. $F{e}_2{O}_3+CO\to 2FeO+C{O}_2$
2. $FeO+CO\to Fe+2CO$
3. $CaO+Si{O}_2\to CaSi{O}_3$
4. All of the above

Q. The final step for the extraction of copper from copper pyrite in Bessemere converter involves the reaction

1. $4C{u}_{2}O+FeS\to 8Cu+FeS{O}_4$
2. $C{u}_{2}S+2C{u}_{2}O\to 6Cu+S{O}_2$
3. $2C{u}_{2}O+FeS\to 4Cu+Fe+S{O}_2$
4. $C{u}_{2}S+2FeO\to 2CuFeCO+S{O}_2$

Q.

Which of the following ions give blue colour in the borax bead test?

1. Fe

2. Cu

3. Co

4. Cr

Q.

A Silvery white metal X is in the form of ribbons. Upon ignition, it burns with a dazzling white flame to form white powder Y. When water is added to the powder Y, it partially dissolves to form a substance Z which is used as an antacid.

1. What is metal X?
2. Name the white powder Y.
3. What is the substance Z?
4. Write the chemical reaction that are taking place.

Q. $Ca{C}_2$ reacts with water to give:

1. Methane
2. Acetylene
3. Ethane
4. Ethylene

Q. In blast furnace iron oxide is reduced by

1. Silica
2. $CO$
3. Carbon
4. Lime stone

Q. Hybridisation of [ScF6]3-

Q.

Which of the following is present as an active ingredient in bleaching powder for bleaching action?

1. $Ca(OCl{)}_2$

2. $Ca{O}_{2}Cl$

3. $CaC{l}_2$

4. $CaOC{l}_2$

Q. what is halogens and sulphur?

Q. is used as dehydrating agent in laboratory.

1. Calcium chloride
2. Sodium chloride
3. Sodium carbonate

Q.

At high temperature, Nitrogen combines with $Ca{C}_2$ to give

1. Calcium cyanide

2. Calcium cyanamide

3. Calcium carbonate

4. Calcium hitride

Q. The difference of water molecules in gypsum and plaster of Paris is:

1. $\frac{5}{2}$
2. $2$
3. $\frac{1}{2}$
4. $1\frac{1}{2}$

Q. In the manufacture of sodium carbonate, the following reactions are involved:
$\text{(A)}\stackrel{\Delta }{\to }\text{(B)}+{\text{CO}}_2$
$\text{(B)}+{\text{H}}_2\text{O}\to \text{(C)}\stackrel{N{H}_{4}Cl}{\to }\text{(D)}$
$\text{(E)}+{\text{CO}}_2\to \text{(F)}$
$\text{(F)}+\text{NaCl}\to \text{G}\stackrel{Heat}{\to }{\text{Na}}_2{\text{CO}}_3+{\text{CO}}_2+{\text{H}}_2\text{O}$
${\text{(D) is a gas which is soluble in H}}_2\text{O}$

Compound (B) is:

1. $Ca{O}_2$
2. $N{a}_{2}O$
3. $CaO$
4. $C{a}_2{O}_2$

Q. $12.5$ g of an impure sample of limestone on heating gives $4.4$ g of carbon dioxide. The percentage purity of $CaC{O}_3$ in the sample is:

1. $72$%
2. $75$%
3. $80$%
4. $85$%

Q. How can quick lime be prepared from slaked lime?

1. By cooling slaked lime
2. None of these
3. By heating slaked lime
4. By adding water

Q. Common salt besides being used in kitchen can also be used as the raw material for making:
(i) washing soda
(ii) bleaching powder
(iii) baking soda
(iv) slaked lime

1. (i) and (ii)
2. (i) and (iii)
3. (i), (ii) and (iv)
4. (i), (iii) and (iv)

Q.

What is the basic purpose of roasting and Calcination? Compare these two processes.

Q.

In the manufacture of Iron, write the chemical equations for the substance which is collected along the Cast iron at the bottom of the furnace.