Question

Calculate the mass of the following.

a) 0.5 mole of N2

gas b) 6.022 x 1023 numbr of N atoms.​

Answer 1

$we \: know \: that \\ moles = \frac{wt}{molecular \: wt}$

$wt = moles \times mol \: wt$

wt=0.5×14=7gms

b

Answer 2

Explanation:

Given -

a) 0.5 mole of N2 gas

b) 6.022 × 10²³ number of N2 atoms.

To Find -

Mass of the following

Now,

Gram Atomic mass of N2 = 14 × 2 =

28 g/mol

As we know that :-

• Mass = mole(n) × Gram atomic mass

Then,

a) mole = 0.5

Gram atomic mass = 28 g/mol

so,

mass = 0.5 × 28

» mass = 14 g

And

b) mole = no. of molecules/6.022 × 10²³

» 6.022 × 10²³/6.022 × 10²³

» 1 mole

so,

mass = 1 × 28

» mass = 28 g