The drug amphetamine, C6H5CH2CH(CH3)NH2, Kb = 7.8 multiplied by 10-4, is usually marketed as the hydrogen bromide salt, C6H5CH2CH(CH3)NH3+Br -, because it is much more stable in this solid form. Determine the pH of a solution made from dissolving 6.43 g of the salt to form 179.0 mL of solution.