Calculate the mass of 3 . 011 × 10 24 atoms of carbon.

We know that: 6 . 022 × 10 23 atoms of carbon = 12 g (atomic mass of carbon) So , 3 . 011 × 10 24 atoms of carbon contains = 12 6 . 022 × 10 23 × 3 . 011 × 10 24 = 12 2 × 10 = 6 × 10 = 60 g Thus, 3 . 011 × 10 24 atoms of carbon contains 60 g of carbon.

Calculate the number of moles in 12 . 044 × 10 25 atoms of phosphorus.

We know that: 6 . 022 × 10 23 atoms of phosphorus = 1 mole So, 12 . 044 × 10 25 atoms of phosphorus = 1 6 . 022 × 10 23 × 12 . 044 × 10 25 = 2 × 10 2 moles = 200 moles Thus, 12 . 044 × 10 25 atoms of phosphorous are 200 moles of atoms.

E M B I B E

Science for Ninth class Part 2 Chemistry>Chapter 3 - Atoms and Molecules>Short Answer Type Questions>Q 19

HARD

9th CBSE

IMPORTANT

Earn 100

What is the number of zinc atoms in a piece of zinc weighing $10 g$ ? (Atomic mass of $Zn = 65 u$ )

Important Questions on Atoms and Molecules

MEDIUM

9th CBSE

IMPORTANT

Science for Ninth class Part 2 Chemistry>Chapter 3 - Atoms and Molecules>Short Answer Type Questions>Q 20

Calculate the mass of

3.011 \times 10^{24}

atoms of carbon.

MEDIUM

9th CBSE

IMPORTANT

Science for Ninth class Part 2 Chemistry>Chapter 3 - Atoms and Molecules>Short Answer Type Questions>Q 21

If

16 g

of oxygen contains

1

mole of oxygen atoms, calculate the mass of one atom of oxygen.

MEDIUM

9th CBSE

IMPORTANT

Science for Ninth class Part 2 Chemistry>Chapter 3 - Atoms and Molecules>Short Answer Type Questions>Q 22

How many atoms are there in

0.25

mole of hydrogen ?

MEDIUM

9th CBSE

IMPORTANT

Science for Ninth class Part 2 Chemistry>Chapter 3 - Atoms and Molecules>Short Answer Type Questions>Q 23

Calculate the number of moles in

12.044 \times 10^{25}

atoms of phosphorus.

HARD

9th CBSE

IMPORTANT

Science for Ninth class Part 2 Chemistry>Chapter 3 - Atoms and Molecules>Short Answer Type Questions>Q 24

Calculate the number of molecules present in a drop of chloroform $({CHCl}_{3})$ weighing $0.0239 g$ . (Atomic masses : $C = 12 u; H = 1 u; Cl = 35.5 u$ )