Question

calculate the number of moles for the 64 gram of oxygen atom

Answer 1

Mass of 1 oxygen atom = 16gm

Therefore 16 gm of oxygenhas 1 mole

=> 16 gm = 1 mole

=> 1 gm = 1/16 mole

=> 64 gm = 1/16 X64 mole

=> 64 gm = 4 mole.

Thus, 64 grams of oxygen contains 4 moles.

Answer 2

Given:

The mass of Oxygen (O) = 64g

To Find:

The number of moles of oxygen

Solution:

We know that the number of moles of a substance in a given sample = $\frac{m}{M}$

Here, m = The given mass of the element or compound

          M = The gram molar mass of the given element or compound

Since the Molar Mass of Oxygen = 16g

(Here we have to take the molar mass of O (16g) and not of oxygen molecule O₂ (32g) because we need to find the number of moles of the oxygen atom.)

⇒ The number of moles of oxygen atom = $\frac{64}{16}$

= 4

Hence, the number of moles of oxygen atom in 64 grams of sample is 4.