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One mole of any substance contains particles equal to 6.022 × 10²³.

1 mole of NH₃ = 6.022 × 10²³ molecules of NH₃

1 mole of HNO₃ = 6.022 × 10²³ molecules of HNO₃

∴ Ratio = \(\frac{6.022\times 10^{23}}{6.022\times 10^{23}}\) = 1 : 1

Mass of 1 atom of hydrogen = 1.008 u 

∴ Mass of 18 atoms of hydrogen = 18 × 1.008 

u = 18.144 u

∴ The mass of 18 atoms of hydrogen = 18.144 u

M = 3 mol L^–1

Mass of NaCl in 1 litre solution = 3 × 58.5 = 175.5 g

Mass of 1 L solution = 1000 × 1.25 = 1250 g

(∵ Density = 1.25 g mL^–1 )

Mass of water in solution = 1250 – 175.5

= 1074.5

Molarity = \(\frac{No.\,of\,moles\,of\,solute}{Mass\,of\,solvent\,in\,kg}\)

= \(\frac{3\,mol}{1.0745\,kg}\)

= 2.79 m

At STP, the volume of 6.022 × 10²³ molecules of H₂ Will be 22.4 L.

Given : Volume of hydrogen at STP = 0.448 L 

To find : Number of moles of hydrogen

Formula :

Number of moles of a gas(n) = \(\frac{Volume\,of\,gas\,at\,STP}{Molar\,volume\,of\,a\,gas}\)

Molar volume of a gas = 22.4 dm³ mol^-1 = 22.4 L at STP

Number of moles of a gas(n) = \(\frac{Volume\,of\,gas\,at\,STP}{Molar\,volume\,of\,a\,gas}\)

= \(\frac{0.448\,L}{22.4\,L\,mol^{-1}}\)

= 0.02 mol.

∴ Number of moles of hydrogen = 0.02 mol

(b) If both assertion and reason are CORRECT, but reason is NOT THE CORRECT explanation of the assertion.

22.4 Litres.

(a) If both assertion and reason are CORRECT and reason is the CORRECT explanation of the assertion.

Correct option: (B) 3.011 x 10²³ 

Number of molecules = n x 6.022 x 10²³

Now, n = \(\cfrac{mass\, of\, oxygen}{molar\, mass\, of\, oxygen}\) = \(\frac{16}{32}\) = 0.5

∴ Number of molecules = 0.5 x 6.022 x 10²³

= 3.011 x 10²³

Correct option: (C) Avogadro’s law

Correct option: (A) 6.022 x 10²³ atoms of C 

Correct option: (C) number of molecules present in one gram molar mass of a substance.

Correct option: (C) 11.2 L of N₂ at N.T.P.

1 gram atom of nitrogen ≡ 22.4 L of N

(molar volume at N.T.P.)

≡ 11.2 L of N₂

Equal volumes of all gases under the conditions of same temperature and pressure contain the same number of molecules.

C) a → iii, b → i, c → ii

Correct option: (B) atoms and molecules

1. unsaturated compounds 

2. ethanol 

3. vinegar 

4. ester 

5. H₂ 

6. – OH (Alcohol) 

7. propene 

8. ethyne (C₂H₂) 

9. ethene (C₂H₄) 

10. 3 

11. substitutional

Ethyne (HC≡CH) explains the ability of carbon atom to form one single bond between one hydrogen and carbon, and one triple bond between carbon and carbon. Ex : H – C≡C – H

D) all of these

The systematic arrangement of elements in a table in horizontal rows and vertical columns is called a periodic table.

Modern periodic law: The physical and chemical properties of the elements are periodic functions of their electronic configurations.

The group of three elements in ascending order of their atomic weights in which the molecular weight of a middle element is the average of the first and third element is called a triad.

Metalloids or semi-metals are elements that have properties that are intermediate between the properties of metals and non-metals.

The horizontal rows and vertical columns of a periodic table are called periods and groups respectively.

Elements are arranged in ascending order of their atomic weights, then every eighth element from starting element has similar properties. This is called an octave.

Anomalous in the arrangement of elements based on increasing atomic mass could be removed when the elements were arranged in order of increasing atomic number, a fundamental property of the element discovered by Moseley.

Elements are classified on the basis of similarities in their properties.

Elements having atomic numbers 90 to 103 are called actinides.

C) Catenation

Correct option is  A) NH₄CNO

Speed : The distance travelled by an object in a unit time is called its speed.

Artificial Satellite : An artificial satellite is a manmade object, launched to revolve around the Earth.

1. An artificial satellite is a manmade object, launched to revolve around the earth. 

2. The size, altitude and design of a satellite depends on its purpose. 

3. Navigation satellites, communication satellites, weather satellites, earth observation satellites, astronomical satellites, Space stations are different types of artificial satellites.

An artificial satellite is a man made object, launched to revolve around the earth.

1. The Space Centre, which was popularly known as SHAR (Sriharikota High Altitude Range) was renamed as Satish Dhawan Space Centre SHAR on September 5, 2002, in the memory of Prof. Satish Dhawan, former Chairman of ISRO. 

2. It is an island of technological excellence where in nature coexists with the techno-crats. 

3. Satish Dhawan Space Centre (SDSC SHAR) is located in Sriharikota, SPSR Nellore, district of Andhra Pradesh. 

4. It is the Spaceport of India. It is one of the main centers of Indian Space Research Organization (ISRO), Department of Space (DOS), Government of India. 

5. This Centre provides world class launch base infrastructure for different launch vehicle/ satellite missions for remote sensing, communication, navigation & scientific purposes. 

6. It is one among the best-known names of the Spaceports of the world today.

The half of the distance between the two atoms in a covalent molecule is called the covalent radius.

Remote sensing IRS satellite is being maintained by ISRO for earth observation.

1) Motion of all particles of a moving object follow a circular path with respect to a fixed centre of axis of rotation. 

2) Then the motion of the object is said to be in rotatory motion.

The major rocket systems used to send the satellites by ISRO are:

1. SLV (Satellite Launch Vehicle), 

2. ASLV (Augmented Satellite Launch Vehicle), 

3. PSLV (Polar Satellite Launch Vehicle), 

4. GSLV (Geosynchronous Satellite Launch Vehicle) and GSLV Mark III

The correct option is B) Nellore.

On 15th February 2017, ISRO launched 104 satellites in a single rocket, it is a world record.

If all the parts of a moving body follow a curved path with respect to a fixed centre or axis of rotation, it is said to be in rotatory motion.

An artificial satellite is a man made object, launched to revolve around the Earth. There are several applications of satellites in our daily life. 

Among them some important are… 

1. Communication – the geostationary satellites are used for communication purposes like long distance telephone calls, interrnet and television broadcasting etc. 

2. Collecting information about space and planets. 

3 Collection of information about 

3. Collection of information about natural resources of earth. 

4. Weather forecasting. 

5. In GPS (Global Positioning System). 

6. Used to transport instruments and passengers to the space to perform experiments.

The correct option is D) all the above.

Rest : An object is said to be at rest if there is no change in its position with respect to its surroundings.

1. If all the parts of a moving body follow a curved path with respect to a fixed centre or axis of rotation, it is said to be in rotatory motion. 

2. Let us understand the rotatory motion of merry-go-round. 

3. While it is moving, persons sitting on hanging chairs like toys move in a curved path around a fixed centre. 

4. The imaginary line passing through the fixed centre is called axis of rotation. 

5. All the parts of the objects move in a curved path with respect to this fixed centre or a fixed axis. This type of motion is known as Rotatory Motion.

The correct option is B) 104.

Rest: Termination or absence of motion.