What is the chemical formula of the compound, lead (II) carbonate?

What is the hybridization of the carbon atom notated with an arrow in the Caffeine molecule shown below? (Note that lone pairs have been omitted to save 3 cents worth of ink…)

Arrange the following three substances: NO+, NO2-, and NO3- in order of decreasing (largest to smallest) N-O bond length.

Consider the following reaction: C3H8 + O2 → CO2 + H2O If 10.0 g of C3H8 were allowed to react with 10.0 g of O2, how many grams of CO2 would be produced?

The cyanate ion (NCO-) has three possible Lewis Structures: Which of these Lewis Structures is/are the most favorable?

All of the following processes are examples of physical transformations except:

What is the hybridization of the carbon atom notated with an arrow in the (S)-Thalidomide molecule shown below? (Hint: Is Carbon the only atom at this line intersection?)  

How carbon atoms are there in 200 molecules of C3H8O?

Which of these compounds is paired incorrectly with its chemical name?

What is the oxidation number of the chlorine atom in perchloric acid (HClO4)?