Core science chemistry>Chapter 3 - Atoms and Molecules>EXERCISE 3B>Q 2

MEDIUM

9th CBSE

IMPORTANT

Earn 100

Give one example each of
(i) a triatomic molecule,
(ii) a tetra-atomic molecule and,
(iii) an octa-atomic molecule of an element.

Important Questions on Atoms and Molecules

HARD

9th CBSE

IMPORTANT

Core science chemistry>Chapter 3 - Atoms and Molecules>EXERCISE 3B>Q 3

Find the ratio by mass of the combining elements in the following compounds.
[At mass of:

Ca = 40, C = 12, O = 16, H = 1, Mg = 24, Cl = 35.5, N = 14, S = 32

]
(a)

{CaCO}_{3}

(b)

{MgCl}_{2}

(c)

H_{2} {SO}_{4}

(d)

C_{2} H_{5} OH

(e)

{NH}_{3}

(f)

Ca (OH)_{2}

MEDIUM

9th CBSE

IMPORTANT

Core science chemistry>Chapter 3 - Atoms and Molecules>EXERCISE 3B>Q 4

Classify each of the following on the basis of their atomicity.
(a)

F_{2}

(b)

{NO}_{2}

(c)

P_{4} O_{10}

(d)

O_{3}

(e)

He

(f)

Ag

MEDIUM

9th CBSE

IMPORTANT

Core science chemistry>Chapter 3 - Atoms and Molecules>EXERCISE 3C>Q 1

The number of times a molecule of a molecular compound is heavier than

\frac{1}{12}

part of

{}^{12}C

is called:

EASY

9th CBSE

IMPORTANT

Core science chemistry>Chapter 3 - Atoms and Molecules>EXERCISE 3C>Q 2

The number of times a molecule of an ionic compound is heavier than

\frac{1}{12}

part of

{}^{12}C

is called:

EASY

9th CBSE

IMPORTANT

Core science chemistry>Chapter 3 - Atoms and Molecules>EXERCISE 3C>Q 3

Molecular mass of glucose $C_{6} H_{12} O_{6}$ is:

$[C = 12, H = 1, O = 16]$

EASY

9th CBSE

IMPORTANT

Core science chemistry>Chapter 3 - Atoms and Molecules>EXERCISE 3C>Q 4

The formula unit mass of $Ca ({HCO}_{3})_{2}$ is:

$[Ca = 40, H = 1, C = 12, O = 16]$

EASY

9th CBSE

IMPORTANT

Core science chemistry>Chapter 3 - Atoms and Molecules>EXERCISE 3C>Q 5

The gram molecular mass of a substance is called its:

EASY

9th CBSE

IMPORTANT

Core science chemistry>Chapter 3 - Atoms and Molecules>EXERCISE 3C>Q 6

Molar mass of a pure chemical compound contains: