Properties and Uses of Calcium Oxide

Q.

Which of the following are exothermic processes?

(1) Dilution of an acid.

(2) Evaporation of water.

(3) Reaction of water with Quicklime.

(4) Sublimation of camphor (crystals).

1. (1) and (2)

2. (1) and (3)

3. (1) and (4)

4. (3) and (4)

Q.

Which of the following is (are) an endothermic process(es)?

1. Dilution of sulphuric acid

2. Sublimation of dry ice

3. Condensation of water vapors

4. Evaporation of water

Q.

What is difference between peroxide and superoxide?

Q.

Lime water reacts with chlorine to form

1. ${\mathrm{CaCl}}_2$

2. ${\mathrm{CaOCl}}_2$

3. $\mathrm{Ca}{\left({\mathrm{ClO}}_3\right)}_2$

4. ${\mathrm{CaO}}_2{\mathrm{Cl}}_2$

Q.

Is the core of Bleaching Powder CaOCl₂ or Ca(OCl)₂ ?

If asked in exam for the formula of Bleaching Powder can we write only "CaOCl₂ ​​​​​​" ?

Q. When limestone is heated around 1270 K we get:

1. Calcium hydroxide and carbon dioxide
2. Quick lime and carbon dioxide
3. Lime water
4. Slaked lime and carbon dioxide

Q. The appearence of colour in solid alkali metal halides is generally due to:

1. F-centres
2. Schottky defect
3. Interstitial positions
4. Frenkel defect

Q.

What is the ionic compound name for ${\mathrm{Al}}_2{\mathrm{O}}_3$?

Q.

${\mathrm{XeF}}_6$ cannot be handled in a glass vessel as it reacts with ${\mathrm{SiO}}_2$ and forms?

Q.

What is the weakest acid?

Q.

What happens when copper rod is dipped in iron sulphate solution?

1. Copper displaces iron.

2. Blue coloured copper sulphate solution is obtained.

3. No reaction takes place

4. Reaction is exothermic

Q.

Match the following compounds (Column-I) with their uses (Column-II) :

Column 1	Column 2
$\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$	Casts of statues
$\mathrm{NaCl}$	White wash
${\mathrm{CaSO}}_4·\frac{1}{2}{\mathrm{H}}_2\mathrm{O}$	Antacid
${\mathrm{CaCO}}_{3_{}}$	Washing soda preparation

Q.

Which is diamagnetic in nature?

1. ${{\mathrm{H}}_2}^{–}$

2. ${{\mathrm{H}}_2}^{+}$

3. ${{\mathrm{He}}_2}^{+}$

4. ${\mathrm{H}}_2$

Q. 3. Which of the following are incorrect? a. P4O10 reacts with CaO to form calcium phosphate b. 2LiNO3(s) -------> Li2O (s) + 2NO2 (g) + 1/2 O2 (g) c. The number of geometrical isomers for the complex [ CoCl2(gly)2] - is 5

Q. The true statement about quick lime is/are:

1. In the manufacture of sodium carbonate from caustic soda.
2. All of the above.
3. Primary material for manufacturing cement.
4. In the purification of sugar

Q.

Name the metal which can be extracted from the ore: Haematite

Q. What happen when quick lime is exposed to atmosphere?

1. (a) and (b) above.
2. Abosorb moisture present in atmosphere
3. Absorb carbon dioxide present in atmosphere
4. Neither a nor b

Q.

In the preparation of iron from haematite $\left(F{e}_2{O}_3\right)$ by the reaction with carbon $F{e}_2{O}_3+C⟶Fe+C{O}_2$
How much 80% pure iron could be produced from 120 kg of 90% pure $F{e}_2{O}_3?$

1. 94.5 kg
2. 120 kg
3. 60.48 kg
4. 116.66 kg

Q.

Identify the type of chemical reaction:

Quicklime reacts vigorously with water releasing a large amount of heat.

Q.

Which of the following compound(s) is/are diamagnetic?

1. ${\mathrm{Na}}_2{\mathrm{O}}_2$

2. ${\mathrm{O}}_3$

3. ${\mathrm{N}}_2\mathrm{O}$

4. ${\mathrm{KO}}_2$

Q.

Copper sulphate solution can be safely kept in a container made of

1. aluminium

2. lead

3. silver

4. zinc

Q. Why do beryllium and magnesium not impart color to the flame in the flame test?

Q.

Give one example of a basic oxide which is insoluble in water.

Q.

Which of the following are exothermic processes?

(1) Dilution of an acid.

(2) Evaporation of water.

(3) Reaction of water with Quicklime.

(4) Sublimation of camphor (crystals).

1. (1) and (2)

2. (1) and (3)

3. (1) and (4)

4. (3) and (4)

Q.

Heat is ______ when limestone is burnt to obtain lime.

Q.

Write a chemical equation showing that Aluminium has more affinity than Iron for Oxygen.

Q. Give the chemical name & formula of chloride of lime. what happens when it is exposed to air. Write Chemical equation.

Q.

Which is the most abundant non-metal on the earth?

Q.

The chemical formula of magnesium sulphate is:

Q.

A sanitary worker uses a white substance having a strong smell of chlorine to clear a water tank. Identify the substance and write the chemical equation for its preparation.