Atoms and Molecules Test

Question 1

1 / -0

Use the following information to answer the next question.

During the 17^th and the 18^th centuries, a few chemists investigated chemical changes quantitatively. By conducting reactions in closed containers, they showed that the products of a chemical change had the same mass as the reactants but the properties of the compounds, before and after the reaction, changed.

The above observation illustrates that, before and after the reaction, the mass of the system is

not conserved and the nature of the compounds does not change.

conserved and the nature of the compounds changes.

conserved but the nature of the compounds does not change.

not conserved but the nature of the compounds changes.

Question 2
1 / -0

Use the following information to answer the next question.

The molecular mass of a substance is the sum of atomic masses of various atoms present in one formula. The molecular mass of a compound X is 44.

The compound X is

A
CO

B
C₂O

C
CO₂

D
C₂O₂

Question 3

1 / -0

Use the following information to answer the next question.

During the chemical reaction between carbon disulfide and oxygen gas, carbon dioxide and sulfur dioxide are yielded. The reaction proceeds with rearrangement of atoms to form different products.

The product sulfur dioxide is formed by combination of sulfur and oxygen, respectively, in the ratio of

2:1

1:2

2:3

3:2

Question 4
1 / -0

How many atoms are present in a phosphorous molecule?

A
One

B
Two

C
Three

D
Four

Question 5
1 / -0

Which of the following elements exists as a monatomic molecule?

A
Hydrogen

B
Nitrogen

C
Oxygen

D
Boron

Question 6
1 / -0

When one atom of carbon combines with two atoms of sulfur, the product formed is

A
CS

B
C₂S

C
CS₂

D
C₂S₂

Question 7
1 / -0

Use the following information to answer the next question.

John Dalton, an English school teacher, put forth the theory of atoms based on chemical laws of combinations.

Which of the following statements is not a postulate of Dalton’s theory?

A
Atoms cannot be created or destroyed.

B
Atoms are extremely tiny invisible particles.

C
Atoms combine in complex fractional ratios.

D
All the atoms of a particular element have identical properties.

Question 8
1 / -0

Atoms combine to form molecules in

A
multiple proportions

B
fractional proportions

C
definite proportions

D
indefinite proportions

Submit Test

Atoms and Molec...

Question 1

not conserved and the nature of the compounds does not change.

conserved and the nature of the compounds changes.

conserved but the nature of the compounds does not change.

not conserved but the nature of the compounds changes.

Question 2

CO

C2O

CO2

C2O2

Question 3

2:1

1:2

2:3

3:2

Question 4

One

Two

Three

Four

Question 5

Hydrogen

Nitrogen

Oxygen

Boron

Question 6

CS

C2S

CS2

C2S2

Question 7

Atoms cannot be created or destroyed.

Atoms are extremely tiny invisible particles.

Atoms combine in complex fractional ratios.

All the atoms of a particular element have identical properties.

Question 8

multiple proportions

fractional proportions

definite proportions

indefinite proportions

User

Question Analysis

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.

C₂O

CO₂

C₂O₂

C₂S

CS₂

C₂S₂