# Question 1a288

Jun 27, 2017

There are 1.00 × 10^26 atoms in 1 L of water.

#### Explanation:

Step 1. Calculate the mass of the water

$\text{Mass" = 1000 color(red)(cancel(color(black)("mL water"))) × "1 g water"/(1 color(red)(cancel(color(black)("mL water")))) = "1000 g water}$

Step 2. Calculate the moles of water

$\text{Moles of water" = 1000 color(red)(cancel(color(black)("g water"))) × "1 mol water"/(18.02 color(red)(cancel(color(black)("g water")))) = "55.49 mol water}$

Step 3. Calculate the molecules of water

"Molecules of H"_2"O" = 55.49 color(red)(cancel(color(black)("mol H"_2"O"))) × (6.022 × 10^23 color(white)(l)"molecules H"_2"O")/(1 color(red)(cancel(color(black)("mol H"_2"O"))))

= 3.342 × 10^25 color(white)(l)"molecules H"_2"O"

Step 4. Calculate the number of atoms

Each molecule of $\text{H"_2"O}$ contains three atoms.

"No. of atoms" = 3.342 × 10^25 color(red)(cancel(color(black)("molecules H"_2"O"))) × "3 atoms"/(1 color(red)(cancel(color(black)("molecule H"_2"O"))))

= 1.00 × 10^26 color(white)(l)"atoms"#