Which of the following has the smallest mass?

(a)

6.023 × 10²³ atoms of He

(b)

1 atom of He

(c)

2 g of He

(d)

1 mole atoms of He

Which of the following is a triatomic molecule?

(a)

Glucose

(b)

Helium

(c)

Carbon dioxide

(d)

Hydrogen

The volume occupied by 4.4 g of CO₂ at S.T.P

(a)

22.4 litre

(b)

2.24 litre

(c)

0.24 litre

(d)

0.1 litre

Mass of 1 mole of Nitrogen atom is

(a)

28 amu

(b)

14 amu

(c)

28 g

(d)

14 g

Which of the following represents 1 amu?

(a)

Mass of a C – 12 atom

(b)

Mass of a hydrogen atom

(c)

1/12^th of the mass of a C – 12 atom

(d)

Mass of O – 16 atom

Which of the following statement is incorrect?

(a)

12 gram of C – 12 contains Avogadro’s number of atoms.

(b)

One mole of oxygen gas contains Avogadro’s number of molecules

(c)

One mole of hydrogen gas contains Avogadro’s number of atoms

(d)

One mole of electrons stands for 6.023 × 10²³ electrons.

The volume occupied by 1 mole of a diatomic gas at S.T.P is

(a)

11.2 litre

(b)

5.6 litre

(c)

22.4 litre

(d)

44.8 litre

In the nucleus of ₂₀Ca⁴⁰, there are 

(a)

20 protons and 40 neutrons

(b)

20 protons and 20 neutrons

(c)

20 protons and 40 electrons

(d)

40 protons and 20 electrons

The gram molecular mass of oxygen molecule is

(a)

16 g

(b)

18 g

(c)

32 g

(d)

17 g

1 mole of any substance contains __________ molecules

(a)

6.023 × 10²³

(b)

6.023 × 10^-23

(c)

3.0115 × 10²³

(d)

12.046 × 10²³

The mass of an atom is measured in ____________

(a)

kg

(b)

amu

(c)

g

(d)

Pm

Atoms of different elements with different atomic numbers, but same mass number are known as _________

(a)

isobars

(b)

isotopes

(c)

isotones

(d)

isomers

Pick out the isotopes among the following pairs

(a)

₆C¹³, ₇N¹⁴

(b)

₁₈Ar⁴, ₂₀Ca⁴

(c)

₆C¹², C₆¹⁴

(d)

₅B¹², ₆C¹³

Which among the following is a homo atomic molecule?

(a)

N₂

(b)

NH₃

(c)

HCl

(d)

N₂O

Mass number is the

(a)

Number of protons

(b)

Sum of protons and electrons

(c)

Number of neutrons

(d)

Sum of protons and neutrons

Which of the following statement regarding an atom is always correct?

(a)

An atom has equal number of electrons and protons

(b)

An atom has equal number of electrons and neutrons

(c)

An atom has equal number of electrons, protons and neutrons

(d)

An atom has equal number of protons and neutrons

Mass of an electron is

(a)

9.1083 x 10^-31kg

(b)

9.1083 x 10^-24kg

(c)

1.67262 x 10^-27kg

(d)

1.67 x 10^-24gm

Which of the following pairs are isotopes?

(a)

Oxygen and ozone

(b)

Ice and water

(c)

NO and NO₂

(d)

Hydrogen and deuterium

The atomic number of an element is 12 and its mass number is 24. The number of electrons, protons and neutrons respectively will be

(a)

12, 12, 24

(b)

24,12,12

(c)

12,12,12

(d)

12, 24,12

Which of the following has an equal number of neutrons and protons?

(a)

protium

(b)

deuterium

(c)

tritium

(d)

magnesium

The smallest particle of an element which involve in a chemical reaction is

(a)

Atom

(b)

Molecule

(c)

Mole

(d)

Avogadro's molecule

₁₇Cl³⁵, ₁₇Cl³⁷ form the pair of

(a)

Isotope

(b)

Isonar

(c)

Isotone

(d)

Isomer

Isotones have equal number of

(a)

Proton

(b)

Electron

(c)

Neutron

(d)

Atom

Which of the contains maximum number of molecules

(a)

1 g of CO₂

(b)

1g of N₂

(c)

1 g of H₂

(d)

1 g of CH₄

One mole of a gas occupies a volume of 22.4 l. This is derived from:

(a)

Berzelius's hypothesis

(b)

Gay- Lussac's law

(c)

Avogadro's law

(d)

Dalton's law

A group of atoms chemically bonded together is a (an):

(a)

Molecule

(b)

Atom

(c)

Salt

(d)

Element

Adding electrons to an atom will result in a (an):

(a)

Molecule

(b)

Anion

(c)

Cation

(d)

Salt

The mass of a molecule of water is:

(a)

3 x 10^-26kg

(b)

3 x 10^-23kg

(c)

1.5 x 10^-26kg

(d)

2.5 x 10^-26kg

Which of the following is a diatomic molecule?

(a)

CO

(b)

CO₂

(c)

SO₃

(d)

PO₄

Isotopes have

(a)

Same physical properties and different chemical properties

(b)

Same chemical properties and different physical properties

(c)

Same physical and chemical properties

(d)

Different physical and chemical properties