Question

An oxygen atom has a mass of 2.66 x 10 g and a glass of water has a mass of 0.050 kg. Use this information to answer the questions below. Be sure your answers have the correct number of significant digits. What is the mass of 1 mole of oxygen atoms? 0x10 Х 5 ? How many moles of oxygen atoms have a mass equal to the mass of a glass of water?

Answer 1

A. 16.0 grams

B. 3.1 mol of oxygen

Step-by-step explanation:

A.

The oxygen atom has mass = 2.66x10^-23g

A mole of oxygen atoms can be calculated as:

[2.66x10^-23/1 oxygen atom] x [6.023x10²³ oxygen atoms/1 mol]

= 16.0 grams of oxygen

So a mole of oxygen has 16.0 grams of O2

B.

For 0.050 kg of water, we have 16.0 grams

(0.050x10³g/kg )x (1mol/16)

= 3.1 mol of oxygen

So 3.1 mol of oxygen has mass which is equal to the mass of water.