How many molecules are in 5.75 mol HBr

5.75 mol HBr = 3.4615 * 10∧24 molecules.

Explanation: The given number of moles of the HBr is 5.75 mol. According to the Avogadro law, one mol of any molecules or atoms is the number of atoms or molecules equal to 6.02 * 10∧23. Hence 5.75 mol will be 5.75 * (6.02 * 10∧23) number of atoms. And it is equal to 3.4615 * 10∧24. Hence the one mole is equal to 6.02 * 10∧23 molecules and 5.75 mol HBr is equal to 3.4615 * 10∧24 molecules.

3.46 x 10²⁴ molecules.

Explanation:

Knowing that every one mole of a substance contains Avogadro's no. of molecules (NA = 6.022 x 10²³).

Using cross multiplication:

1.0 mole of HBr → 6.022 x 10²³ molecules.

5.75 mole of HBr →? molecules.

∴ The no. of molecules of HBr are in 5.75 mol = (6.022 x 10²³ molecules) (5.75 mole) / (1.0 mol) = 3.46 x 10²⁴ molecules.