lead sulphate
lead nitrate
lead chromate
lead iodide
Lead nitrate, \( \text{Pb(NO}_3)_2 \), is a soluble colorless compound. Confirmatory tests for ions usually involve the formation of a precipitate or a distinctly colored complex.
Lead sulphate (white precipitate), lead chromate (yellow precipitate), and lead iodide (yellow precipitate) are all used as confirmatory tests for lead(II) ions.
Since lead nitrate is colorless and soluble, it's not used as a confirmatory test.
Let one focus of the hyperbola $ \frac{x^2}{a^2} - \frac{y^2}{b^2} = 1 $ be at $ (\sqrt{10}, 0) $, and the corresponding directrix be $ x = \frac{\sqrt{10}}{2} $. If $ e $ and $ l $ are the eccentricity and the latus rectum respectively, then $ 9(e^2 + l) $ is equal to:
The largest $ n \in \mathbb{N} $ such that $ 3^n $ divides 50! is: