1.If a nitrate (NO₃) and ammonia (NH₃) solution are labeled as 280 mg/L NO₃-N and 280 mg/L NH₃-N respectively, what is the corresponding concentration (mM) of NO₃ and NH3?

2. Calculate the pH of a 0.025MC₅H₅N (pyridine) solution. The K_bfor pyridine is 1.710⁹.pH =.

The pH of a 0.30 M solution of a weak base is 10.62. What is the K_b of the base? K_b = 10 Enter your answer in scientific notation.