A compound contains only C, H, and N. Combustion of a 40.28 g sample of the compound produces 38.46 g of carbon dioxide, 47.25 g of water, and some nitrogen gas. A separate experiment determines the molecular mass of the compound to be 138.3 g/mol. Determine the empirical formula and molecular formula for the compound.

What does a particular point on a line of a phase diagram represent? o a. the maximum temperature a substance can exist at without bonds breaking b. the pressure created by the kinetic energy of molecules at a particular temperature c. the melting point or boiling point of a substance at a specific pressure d. the conditions in which temperature and pressure have equal effects on a substance

Asample of aluminum foil contains 8.60 × 1023 atoms. what is the mass of the foil?

Abeaker with 2.00×102 ml of an acetic acid buffer with a ph of 5.000 is sitting on a benchtop. the total molarity of acid and conjugate base in this buffer is 0.100 m. a student adds 4.70 ml of a 0.360 m hcl solution to the beaker. how much will the ph change? the pka of acetic acid is 4.740.