pure sample of an organic molecule has the formula CxHyOz. If x = 12, y = 21, and z = 2. Calculate the percent by mass of oxygen in the formula. Round your result to the nearest tenth number; do not enter a % sign in your answer.

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Balance each equation by inserting coefficients as needed. equation 1: equation 2: C3H8 + O₂ CO,+H,O P4O10 + H₂O → H₂PO4

How many grams of NaCl should be produced if you start with 1.0 g of sodium bicarbonate. This conversion will require three conversion factors. Start with 1.0 g NaHCO3. Then use a conversion factor that converts that to moles. Then use the balanced equation to convert from moles of NaHCO3 to moles of NaCl. Then use a conversion factor to convert to grams.

A pure sample of an organic molecule has the formula CxHyOz. If x = 11, y = 13, and z = 2. Calculate the percent by mass of oxygen in the formula. Round your result to the nearest tenth number; do not enter a % sign in your answer.

43. One of the ingredients in the Native American stomachache remedy derived from common chokecherry is caffeic acid which is comprised of carbon, hydrogen, and oxygen only. Combustion of 1.00  102 mg of caffeic acid yielded 220 mg of CO2 and 40.3 mg of H2O. Determine the empirical formula of caffeic acid. You may check your answer by looking up the answer, but do not use the formula to solve the problem.

Menthol, the substance we can smell in mentholated cough drops, is composed of CC, HH, and OO. A 9.045×10−2-mgmg sample of menthol is combusted, producing 0.2546 mgmg of CO2CO2 and 0.1043 mgmg of H2OH2O. What is the empirical formula for menthol?         Express your answer as a chemical formula.