Question

Calculate the mass of the following:

(a) 0.5 mole of N gas( mass from mole of molecules)

(b) 0.5 mole of N atoms (mass from mole of atoms)

(c) 3.011× 10 number of N atoms (mass from number)
​

Answer 1

Answer :-

(a) Mass of 0.5 mole of N gas:

Mole = Given Mass/Molar Mass

=> 0.5 = Given Mass/28

=> Given Mass = 0.5 x 28 = 14g

Therefore, mass of 0.5 mole of N gas is 14 grams.

(b) Mass of 0.5 mole of N atoms:

Mole = Given Mass / Molar mass

=> 0.5 = Given Mass / 14

=> Given Mass = 0.5 x 14 = 7g

Therefore, mass of 0.5 mole of N atoms is 7 grams.

(c) 3.011 x 10^23 no. of N atoms:

Mole = No.of particles/Avagadro's no.

Mole = 3.011x10^23/6.022x10^23

=> Mole = 0.5

But, Mole = Given mass/Molar mass

=> 0.5 = Given mass / 14

=> Given Mass = 0.5 x 14 = 7g

Therefore, mass of 3.011x10^23 N atoms is 7 grams.

Answer 2

(a)Molar mass of N2=14×2=28

no. of moles =given mass /molar mass

0.5=given mass /28

given mass=28×0.5

=14g

(b)Molar mass of N=14g

no. of moles =given mass /molar mass

given mass=0.5×14

=7g

(c)Molar mass of N=14g

no. of atoms=given mass /molar mass ×avagadro no.

given mass=no. of atoms×molar mass /avagadro no.

=3.011×10×14/6.022×10^23

=7×10^-22

HOPE IT WILL HELP YOU. .