Find out the mass of 12 . 044 × 10 23 atoms of magnesium. (Given, the mass of Mg = 24 u ).

The atomic mass of Mg = 24 u Hence, its gram molecular mass is 24 g . 24 g of Mg contains 6 . 022 × 10 23 number of atoms. A collection of 6 . 022 × 10 23 particles/atoms/molecules/ions is called one mole. So, 1 mole of Mg = 24 g = 6 . 022 × 10 23 molecules Therefore, 12 . 044 × 10 23 atoms contain = 12 . 044 × 10 23 6 . 022 × 10 23 = 2 moles. Mass of 2 moles of magnesium is 24 g × 2 = 48 g

E M B I B E

Essentials of Chemistry>Chapter 9 - Sample Paper>Sample Paper 2>Q 6

EASY

9th CBSE

IMPORTANT

Earn 100

Can a solution be heterogeneous?

Important Questions on Sample Paper

MEDIUM

9th CBSE

IMPORTANT

Essentials of Chemistry>Chapter 9 - Sample Paper>Sample Paper 2>Q 7

Give reasons: Steam produces more severe burns than water.

MEDIUM

9th CBSE

IMPORTANT

Essentials of Chemistry>Chapter 9 - Sample Paper>Sample Paper 2>Q 7

Give reasons: We are able to sip hot tea faster from a saucer than a cup.

MEDIUM

9th CBSE

IMPORTANT

Essentials of Chemistry>Chapter 9 - Sample Paper>Sample Paper 2>Q 7

Give Reasons: Water kept in earthen pot becomes cool during summer.

EASY

9th CBSE

IMPORTANT

Essentials of Chemistry>Chapter 9 - Sample Paper>Sample Paper 2>Q 8

Hydrogen has three isotopes which are written as:

{}_{1}^{1}H

,

{}_{1}^{2}H

,

{}_{1}^{3}H

Explain why these isotopes
(A) have identical chemical properties.
(B) are electrically neutral.
(C) differ in their mass.

EASY

9th CBSE

IMPORTANT

Essentials of Chemistry>Chapter 9 - Sample Paper>Sample Paper 2>Q 9

Write the names of the compounds represented by the following formulae :

(a) ${Na}_{2} S$
(b) ${KNO}_{3}$

EASY

9th CBSE

IMPORTANT

Essentials of Chemistry>Chapter 9 - Sample Paper>Sample Paper 2>Q 9

Write the chemical formulae of:
(a) Aluminium chloride
(b) Magnesium oxide.

MEDIUM

9th CBSE

IMPORTANT

Essentials of Chemistry>Chapter 9 - Sample Paper>Sample Paper 2>Q 9

Find out the mass of $12.044 \times 10^{23}$ atoms of magnesium. (Given, the mass of $Mg = 24 u$ ).

MEDIUM

9th CBSE

IMPORTANT

Essentials of Chemistry>Chapter 9 - Sample Paper>Sample Paper 2>Q 10

The following substances are added to water kept in a beaker.
(i) Kerosene
(ii) Sugar
(iii) Soap
(iv) Milk
Choose the mixture which is a
(a) Colloidal solution
(b) True solution
(c) Immiscible liquids

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