Question

Q21. Calculate -

(a) Formula unit mass of MgCl 2 (atomic mass of Mg - 24 , Cl-35.5) .

(b) Calculate the number of particles in 0.1 mole of carbon atoms.​

Answer 1

Answer:

a)we have two chorine atoms in this particular molecule, we simply multiply the molar mass of 1 Cl atom by 2 so that we have 70.90 g/mol of Cl. Was this answer helpful?

b)According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 6.023\times 10^{23}6.023×10

23

of particles.

Standard condition of temperature (STP) is 273 K and atmospheric pressure is 1 atmosphere respectively.

1 mole of carbon atoms contain = 6.023\times 10^{23}6.023×10

23

particles of carbon

Thus 0.1 mole of carbon atoms contain = \frac{6.023\times 10^{23}}{1}\times 0.1=6.023\times 10^{22}

1

6.023×10

23

×0.1=6.023×10

22

particles of carbon

Thus 6.023\times 10^{22}6.023×10

22

particles are present in 0.1 mole of carbon atoms