Question

5. Calculate the number of atoms/molecules for:
a) 10 moles of carbon dioxide (CO2)
b) 16 grams of CH4.
c) 3.2 moles of Sulphur(S8)​

Answer 1

Answer:

mole = W/Mw =N/Na

a) N = 10Na

(10 = N/Na)

Atoms = 30Na

b)

n = 16/16 =1

N = Na

Atom = 4Na

c)

n = 3.2

N = 3.2Na

Answer 2

Answer:

a ) .

We know :

1 moles of carbon dioxide contains 6.023 × 10²³ molecules .

So, 10 moles contains = 10 × 6.023 × 10²³ molecules .

= > 6.023 × 10²⁴ molecules .

b ) .

Molar mass of CH₄ = 12+ 4 = 16 g

No. of moles = 16 / 16 = 1 .

No. of atoms = 6.023 × 10²³ atoms.

c ) .

1 moles contains 6.023 × 10²³ molecules of S₈

So, 3.2 moles contains = 3.2 × 6.023 × 10²³ molecules .

= > 1.92 × 10²⁴  molecules.