Question

calculate the total number of electron present in 9 ml of h2o

Answer 1

According to the units system:

1 l = 10^-3 (m^3)

1 ml = 10^-3 l = 10^-6 (m^3)

The density of water is 1000 kg/(m^3)

So, the mass of water in 1 ml is:

M = D*V = 1 gm

Thus, 1 ml of water has a mass of 1 gm.

Therefore, 9 ml - 9 gm.

Molar mass of water is 18 gm.

Thus, 9 gm will have 0.5 moles of water.

1 mole has Avogadro's number of particles:

=> 0.5 moles will have = N/2 particles

where N = 6.023*(10^23)

Number of electrons in one molecule of water is: 1(H) + 8(O) + 1(H) = 10 electrons.

So, in 0.5 moles of water:

Number of electrons = {(6.023*(10^23))/2}* 10

Number of electrons = 3.011*(10^24) electrons