In 2.00 mol of NH4Cl there are  × 1024 hydrogen atoms.

To find the number of hydrogen atoms in 2.00 mol of NH4Cl, follow these steps:

1. Identify the number of hydrogen atoms in one molecule of NH4Cl. In NH4Cl, there are 4 hydrogen atoms.

2. Use Avogadro's number to find the number of molecules in one mole. Avogadro's number is 6.022 x 10^23, so there are 6.022 x 10^23 molecules in one mole.

3. Multiply the number of hydrogen atoms in one molecule by Avogadro's number to find the number of hydrogen atoms in one mole. 4 x 6.022 x 10^23 = 2.4088 x 10^24 hydrogen atoms.

4. Multiply the number of hydrogen atoms in one mole by the number of moles. 2.00 mol x 2.4088 x 10^24 = 4.8176 x 10^24 hydrogen atoms.

So, in 2.00 mol of NH4Cl, there are approximately 4.82 x 10^24 hydrogen atoms.