Q3 of 27 Page 47

In 90 gram of water

How many molecules are present?

Given: Mass of water = 90g

Gram molecular mass of H2O = 18g


To calculate the number of molecules, first we apply the formula:





Number of gram molecules = 5


Now, number of molecules = 5 × 6.022 × 1023


= 3.01 × 1024


Thus, number of molecules of 90 gm of water is 3.011 × 1024


More from this chapter

All 27 →
2

Examine the samples given:

a. 20 g of He


b. 44.8 L of NH3 at STP


c. 67.2 L of N2 at STP


d. 1 mol of H2SO4


e. 180 g of water What will be the ascending order of the total number of atoms in each sample?

 2

Examine the samples given:

a. 20 g of He


b. 44.8 L of NH3 at STP


c. 67.2 L of N2 at STP


d. 1 mol of H2SO4


e. 180 g of water


What will be the masses of samples b, c and d?

 3

In 90 gram of water

What will be the total number of atoms?

 3

In 90 gram of water

What will be the total number of electrons in this total number of particles?