Here's how to calculate the mass of 1.50 moles of hydrogen peroxide (H₂O₂):

1. Find the molar mass of hydrogen peroxide:

* Hydrogen (H) has a molar mass of 1.01 g/mol.

* Oxygen (O) has a molar mass of 16.00 g/mol.

* H₂O₂ has two hydrogen atoms and two oxygen atoms: (2 * 1.01 g/mol) + (2 * 16.00 g/mol) = 34.02 g/mol

2. Use the molar mass to convert moles to grams:

* Mass (g) = moles * molar mass

* Mass (g) = 1.50 mol * 34.02 g/mol

* Mass (g) = 51.03 g

Therefore, the mass of 1.50 moles of hydrogen peroxide is 51.03 grams.