Answer:
Number of moles of oxygen atoms that weigh the same as a glass of water = 3.12 moles
Note: This question lacks certain figures. Below is a complete similar question.
An oxygen atom weighs 2.66*10^-23 g and a glass of water weighs 0.050 kg. What is the weight of one mole of oxygen atoms? Round your result to three significant figures. How many moles of oxygen atoms have a weight equal to the weight of a glass of water? Round your answer to two significant figures.
Explanation:
One mole of a substance comprises the Avogadro number of particles, which is 6.02 * 10²³.
Hence, one mole of oxygen atoms contains 6.02*10²³ atoms.
Weight of a single oxygen atom = 2.66*10⁻²³ g
Weight of one mole of oxygen atoms = weight of a single atom multiplied by the number of atoms in one mole.
Weight of one mole of oxygen atoms = 2.66*10⁻²³ g * 6.02*10²³ = 16.01 g
A glass of water weighs = 0.050 kg or 50 g.
To calculate how many moles of oxygen atoms weigh the same as a glass of water (i.e., 50 g), the following formula is applied;
number of moles = mass/molar mass
mass of oxygen atoms = 50 g, molar mass or weight of one mole of oxygen atoms = 16.01 g
Thus, the number of moles of oxygen atoms = 50 g / 16.01 g = 3.12 moles
