Question

An oxygen atom has a mass of 2.66*10^-23 and a glass of water has a mass of 0.050 kg. What is the mass of 1 mole of oxygen atoms? Round your answer to 3 significant digits. How many moles of oxygen atoms have a mass equal to the mass of a glass of water? Round your answer to 2 significant digits.

Answer 1

Answer : The mass of 1 mole of oxygen atoms is, 16.0 grams

The moles of oxygen atoms is, 3.1 moles

Explanation :

First we have to calculate the mass of 1 mole of oxygen atoms.

Given : Mass of 1 oxygen atom =
`2.66* 10^(-23)g`

As, 1 atom of oxygen has mass =
`2.66* 10^(-23)g`

So,
`6.022* 10^(23)` atom of oxygen has mass =
`(6.022* 10^(23))* (2.66* 10^(-23))=16.0g`

Thus, the mass of 1 mole of oxygen atoms is, 16.0 g

Now we have to calculate the moles of oxygen atoms.

As per question, the mass of oxygen atoms = mass of a glass of water = 0.050 kg = 50 g

Formula used :

`\text{Moles of oxygen atoms}=\frac{\text{Mass of oxygen atoms}}{\text{Molar mass of oxygen atoms}}`

Molar mass of oxygen atom = 16 g/mole

`\text{Moles of oxygen atoms}=(50g)/(16g/mole)=3.1mole`

Therefore, the moles of oxygen atoms is, 3.1 moles

Answer 2

16.0 g; 3.1 mol

Step-by-step explanation:

(a) Mass of O atoms

Mass = 6.022 × 10^23 atoms × (2.66 × 10^-23 g/1 atom) = 16.0 g

(b) Moles of O atoms

0.050 kg = 50 g

Moles = 50 g × (1 mol/16.0 g) = 3.1 mol