Question

If you have 20 g of H2, how many atoms of hydrogen is that?

Answer 1

20 g of
`\(H_2\)` contains approximately
`\(6.022 * 10^(24)\)` hydrogen atoms, calculated using the mole concept and Avogadro's number.

To determine the number of hydrogen atoms in 20 g of
`\(H_2\)`, we'll use the concept of moles and Avogadro's number. The molar mass of
`\(H_2\)` is the sum of the atomic masses of two hydrogen atoms, which is approximately 2 g/mol.

First, calculate the moles of
`\(H_2\)` using the formula:

`\[ \text{Moles} = \frac{\text{Mass}}{\text{Molar Mass}} \]`

`\[ \text{Moles of } H_2 = \frac{20 \, \text{g}}{2 \, \text{g/mol}} = 10 \, \text{mol} \]`

Now, use Avogadro's number
`(\(6.022 * 10^(23)\) mol\(^(-1)\))` to find the number of atoms:

`\[ \text{Number of atoms} = \text{Moles} * \text{Avogadro's number} \]`

`\[ \text{Number of atoms} = 10 \, \text{mol} * (6.022 * 10^(23) \, \text{mol}^(-1)) = 6.022 * 10^(24) \, \text{atoms} \]`

Therefore, 20 g of
`\(H_2\)` corresponds to approximately
`\(6.022 * 10^(24)\)` hydrogen atoms.

Answer 2

The molar mass of hydrogen is approximately 1 g/mol. This means that 1 mole of hydrogen atoms has a mass of 1 gram. So, to find the number of atoms in 20 grams of hydrogen, we need to first find how many moles of hydrogen there are, using the following equation:

moles of hydrogen = mass of hydrogen / molar mass of hydrogen

Plugging in the values, we get:

moles of hydrogen = 20 g / 1 g/mol = 20 mol

So there are 20 moles of hydrogen present in 20 g of hydrogen.

Finally, we can find the number of atoms of hydrogen using Avogadro's number, which gives the number of particles (such as atoms, molecules, or ions) in one mole of a substance. Avogadro's number is approximately 6.02 x 10^23 particles per mole. So we can find the number of atoms of hydrogen as follows:

number of atoms of hydrogen = moles of hydrogen x Avogadro's number

Plugging in the values, we get:

number of atoms of hydrogen = 20 mol x 6.02 x 10^23 atoms/mol

number of atoms of hydrogen = 1.204 x 10^25 atoms

Therefore, there are approximately 1.204 x 10^25 atoms of hydrogen in 20 g of H2.